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USB (VCP) communication issues #1709

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carmarri opened this issue Nov 3, 2016 · 24 comments
Closed

USB (VCP) communication issues #1709

carmarri opened this issue Nov 3, 2016 · 24 comments

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@carmarri
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carmarri commented Nov 3, 2016

Hello,

I've noticed some issues in the USB communication. I'll try to give us much information as possible
More information (data, pictures, etc) on previous discussion on Raspberry PI forum: https://www.raspberrypi.org/forums/viewtopic.php?f=33&t=161922&p=1062581#p1062581

Introduction
I'm developing a SO library (C/C++) for one of my company products, using codeblocks and cross-compiling with GCC from Ubuntu Mate. This hardware product uses FTDI and is connected to the Raspberry PI using a USB cable. At the software layer, the communication is performed using the Virtual Comm Port, since I want to allow the Library to detect any port, no matter if its VCP or a physical port. In order to handle the communications I use the kernel library commands open(), close(), read(), write(), ioctl(), termios structures, etc.
The Library has been tested from the raspberry PI through Lazarus (free-pascal) and Python, having both the same behaviour/issue.

Issue
If I open the port, send and receive data to/from my device, the communication runs perfect until I close the port. So what I've noticed is that, randomly (maybe once every 5 times), when I try to open the port, the port is succesfully opened (all functions return succeed) but no communication can be performed. I mean, Once the port is open, I send a fixed ASCII command to our product and I expect a fixed response (product detection through an ID). The command is sent sucessfully, in fact, no errors are reported by the write() function, then I've a timeout in the response and I don't get any data. The command should be received within 20-30ms and I've a timeout of 1 second, which I've experimentally increased during testing up to 10 seconds. The bytes available in the buffer/ports are zero. Then, no matter if I send more commands or not, the communication still fails.
So if I open the port and I'm able to communicate, everything goes fine until I close the port; but if the first command fails, then the communication keeps failing until I close the port.
I've monitored the TTL serial lines after the FTDI in my device (see link) and I've noticed that when the communication fails at the software layer, it is actually being performed at the hardware layer.
I'm using a Raspbian Lite Image to which I've installed LXDE and dependencies, since the application is targeting an embedded touch-screen system.

Testing/Debug

  • The Raspberry PI is up to date, all packages are up to date.
  • Tested on a dirty and clean Debian/Raspbian update.
  • My device has both USB and RS232 ports, so I've tryed connecting to the physical serial port of the Raspberry PI and the SO library works fine 100% of times, so it always connects and communicates fine.
  • I've tested other USB to RS232 chips and converters and the same error is repeated.
  • The same hardware has been tested from a PC and no problems are reported, so is not, an isue of the hardware.
  • Different baudrates have been tested and the problem still occurs.
  • The very same SO code has been compiled and tested on a Linux desktop PC and everything works fine, so it's not an issue of the Library.
  • The very same library and test programs have been tested in Raspberry PI v3, v2 and v1 and the same problem occurs, so the problem is repeatable and consistant.
  • The very same SO and test programs (copy-paste) have been tested in other ARM platforms, also with Debian: BeagleBone black, Cubie-board, UDOO Neo. and everything works fine, the problem does not exists, so clearly it is related to the Raspberry PI. Based on this test I suppose that the problem is not in the FTDI or VCP drivers, since I guess the drivers are the same and used along different distributions and platforms (am I right?).
  • The error does not occur if I repeat the sequence open-communicate-close continuously. I mean, I have a button that I click every time I want to open and close the communication. If I open the port immediately after that it has been closed, the issue is minimized and rarely occurs (press the button at certain rate, like every 1s). But if I wait for some seconds after I close the port, then the issue occurs (maybe not, as I said this is random).

I'm not sure what could be the problem but maybe there is a problem while handling the USB interrupts (kernel issue); I initially though that could be something related to UART syncronization but this does not make sense in USB Virtual Comm Ports, since everything is software, handled by the USB driver.

It took me one month of testing before I had enough data to report this, so please, take this seriously.

Since I work indirectly for the automotive industry and there are many companies all over the globe pretending to develop projects for the Raspberry PI, it will be a pitty that the Raspberry PI is discarted or not recommended if they start noticing this kind of issues.

Please, feel free to ask for more data if you need it.

Thank you very much in advance.

@pelwell
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pelwell commented Nov 3, 2016

You will have a better chance of getting to a solution if you cut your application down to a small test program that still exhibits the problem and upload the source somewhere - a Gist, Pastbin, Google Drive etc. - together with any instructions you think are relevant. An ideal test would involve looping back the USB serial port to the onboard UART, with a small application to emulate your device.

@P33M
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P33M commented Nov 3, 2016

It would also be useful if we had an indication of how often this problem occurs - is it 1 time in 10? 10000? Does it recur within seconds or hours?

In addition to cutting the application down to minimal source/test harness, finding out what provokes the bug more reliably (e.g. repeatedly opening/closing the device in a naive fashion) would make the likelihood of finding it a lot greater.

Edit: you say this is reproducible ~20% of the time. That's useful - if we can get a test case that gives us a broken state after ~1 minute then we can iterate.

@carmarri
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carmarri commented Nov 3, 2016

Hi,

@P33M I've already given that info in my post. It is completely random, but it usually happen 1 time in 5-10.

What it is very important and I forgot to add is (I'll edit the post):

  • The error does not occur if I repeat the sequence open-communicate-close continuously. I mean, I have a button that I click every time I want to open and close the communication. If I open the port immediately after that it has been closed, the issue is minimized and rarely occurs (press the button at certain rate, like every 1s). But if I wait for some seconds after I close the port, then the issue occurs (maybe not, as I said this is random).

@pelwell I'll discuss this with my boss and I'll see what I can do. I guess that I can post something, since the code is very similar to many Serial port communication codes for C/C++ in Linux, that can be found on the net. I guess that you would need a similar setup, but this is delicate. I guess that I would be allowed to send a demo version of the hardware with an NDA to somebody at the Raspbeery PI foundation.

@pelwell
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pelwell commented Nov 3, 2016

If the problem is in the USB serial port side as you claim then a simple test harness that opens a serial port on the Pi (/dev/serial0), waits for the greeting and sends the response, ought to be adequate - just attach the pins on the FTDI to header pins 6, 8 and 10 (you don't say if you are using flow control).

@ghost
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ghost commented Nov 5, 2016

@carmarri:

If you suspect this is a USB issue, you might want to see if you can get a trace with usbmon. It's a free driver that's included with Linux that let's you snoop the USB information going into and out of the USB driver.

Also, if your company have a few $$$ at your disposal, you can try buying a USB bus analyzer. These can be on the pricey side($1,000) but can be very useful for these kinds of issues. Some standard logic analyzer's have some USB support, but they are very limited compared to an actual bus analyzer.

Finally, I think some of FTDI's products are garbage even though they seem to be very, very popular. I tried using them 15 year ago for something and I was having all kinds of issues similar to yours. I think they have improved somewhat since then though.

@lategoodbye
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@carmarri Does dmesg show anything in case the issue occurs?

@carmarri
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Hi,

First of all, sorry for the delay, but have been out of the country for the last week on a work trip.

@pelwell As I said on the initial message, I already tested communication through the physical UART ports using the very same software/settings and it is working fine. The problem is on the USB. My device is USB based (FTDI) so it is connected to the Raspberry PI using a USB cable.

@Electron752 Thanks for the suggestion. I'll try usbmon. I don't think my boss will be happy to buy a USB Analyzer to debug this issue. Anyway I think this is not related to FTDI, since, as I said in my initial message, I've tried different serial to USB converters with the very same result (Cypress, SiLabs and another Chinesse product). FTDI is probably not the best solution (I don't have much experience with others) but it has been reliably working for the last 8 years. Do you have any suggestion to use a different brand?

@lategoodbye dmesg does not show any message when the error occurs. The messages available are from the boot sequence:
registered new interface usbserial
registered new interface usbserial_generic
USB Serial support registered for generic
registered new interface driver for ftdi_sio
USB Serial support registered for FTDI USB Serial Device
FTDI USB Serial Device converter detected
Detected FT232RL
FTDI USB Serial Device converter now attached to ttyUSB0

*** As a sumary of the issue: My device can be connected to the Raspberry PI using either USB or serial cable. With Serial connected to the physical UART pins of the PI, no error detected. When connected using USB the problem occurs. The problem does occurs on board v1, v2 and v3, but not on other boards like BeagleBone, UDOO, etc. I've monitored the serial lines in my device (before the FTDI chip) and when the issue appears the command is received from the computer and a response is sent to it, but an empty buffer is reported on the C++ code.

Regards,
Carles

@pelwell
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pelwell commented Nov 14, 2016

@carmarri I think you have misunderstood. I am suggesting that you can use a working "physical" UART to emulate the greeting handshake in your device, which you then connect to the FTDI USB UART:

Pi application -> FTDI UART -> Pi onboard UART -> simple emulated device

@carmarri
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Hi @pelwell sorry but I indeed missunderstood what you meant. I guess that you want to confirm that this is not a hardware problem. Well, I can confirm you that it is not. since it has been tested with other FTDI-based product and the same problem occurs, while in other boards does not occur. Also tested this hardware in x86 Laptop/Desktop PCs and the problem does not occur either.

@pelwell
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pelwell commented Nov 14, 2016

No, that isn't what I want. I believe that you are experiencing a real problem, I am assuming for now that it isn't caused be a faulty device, and I would like to be able to reproduce the problem here.

Your options are:

  1. Send us all of the hardware and application software discussed. This could involve NDAs and lawyers.
  2. Send us the hardware and some simple test code. Perhaps not as bad as 1, but still not great.
  3. Demonstrate that the same problem can be observed with an FTDI cable and an emulator running on a Pi. All you then need to send us is the test app and an FTDI cable, but we may even be able to observe it with one of the many cables we already have.

I assumed that option 3 would be easier all round, so that is what I have been advocating.

@carmarri
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Hi @pelwell
I've just tested what you suggested in 3). I've created a c++ program that emulates the behaviour of our hardware and I've it running on a Raspberry PI v1, then I'm using a FTDI serial to USB cable connected to the physical serial port of the first PI and connected through USB to the second PI. So the second PI (v3) is running my test application (the same I was using in the inital test) and the same behaviour occurred.
Just in case I did any mistake on the C/C++ code of the test application or the emulator I've tryed creating both emulator and test program in Python too, but with the very same beahavior/issues. So definitely, this is nothing to do with my code. or my hardware.

I'll arrange some test code for you. Please, send me a p.m. with an email address. This is a little bit embarrassing, but my boss is also asking for Name, work address, or some ID that could identify you.

@Electron752 I've tested usbmon, but I'm not sure how to understand what is going on. I've noticed different set of messages between both situations (port opened and communicating vs opened and no communication); the main thing I've noticed is that when everything goes fine there is some kind of periodic control messages on the USB bus, no matter if its transmiting useful data or not (this does not happen when the issue occurs). So I guess, that for some reasone, the USB communication is not being started, but no error is reported to the kernel, so open() returns "no error".

@pelwell
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pelwell commented Nov 16, 2016

GitHub doesn't do PM, but if you email me (phil@raspberrypi.org) saying what information you need I'll get back to you.

@carmarri
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Thanks @pelwell I'll contact you tomorrow. I really appreciate your time and patience :-)

@pelwell
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pelwell commented Nov 24, 2016

With the help of the supplied test code we've been able to reproduce the problem, capture traces using a USB analyzer and the kernel usbmon facility. Both show long periods where the device isn't polled for data, and if we don't poll it can't send anything. These gaps correspond to the stalls in the data flow as seen by the test client, so there is clear evidence of a bug.

The resident expert on the USB stack (@P33M) is looking forward to opening that can of worms again.

@P33M
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P33M commented Apr 24, 2017

@carmarri
Do you still see the issue if you set the parameter dwc_otg.nak_holdoff=0 in /boot/cmdline.txt? Your test program passes for me with this set. Note that this will degrade performance due to excessive interrupts as it's a workaround (or confirmation of where to look for a bug) rather than a fix.

@P33M
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P33M commented Apr 24, 2017

I now have both usbmon and analyzer traces for each side of the interface (host driver vs actual hardware).

It appears that a bulk URB is submitted to the HCD for the IN endpoint of the FTDI device, but the USB transfer doesn't take place for upwards of 700ms. The completion callback is then triggered. Prior to this, a pile of transfers were submitted to the control endpoint which presumably form part of the usb-serial driver's initialisation of the device.

There's only a few places in the driver where nak_holdoff can alter the state flow so this narrows down the scope of investigation considerably.

@P33M P33M reopened this Apr 24, 2017
@P33M
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P33M commented Apr 25, 2017

The cause of the issue has been identified - our nak_holdoff mechanism doesn't take into account URBs being removed from the queue as a trigger to reset the qh->nak_frame count.

The hold-off records the last frame number that a NAK response was received, plus a configurable interval. The queue of subsequent transfers to the endpoint would then be ignored by the driver until (frame_number + interval) had expired.

Long story short, this could cause delays of up to 2 seconds in getting data from a bulk or control full- or low-speed IN endpoint as a stale qh->nak_frame value would erroneously throttle the endpoint by skipping the endpoint queue for a large interval until the frame counter wrapped back around to the nak_frame value. Setting nak_holdoff=0 avoided this path as queues are unconditionally executed.

I've got a 2-line fix that appears to resolve the issue in the test program. Will push this in a PR shortly.

@carmarri
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Hi! I'm really sorry for the delay in my reply but I'm just back to the office after having taken some days off.
First of all, THANK YOU VERY MUCH, this is a big improvement.

Phil @P33M, do I need to change the value "dwc_otg.nak_holdoff=0" in my system or will that be internally fixed in the next system update? Based on your words I guess this was only a patch to bypass the issue.

@P33M
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P33M commented Apr 26, 2017

Setting dwc_otg.nak_holdoff=0 is suboptimal for a lot of use-cases. It's a workaround until the fix is available (first in rpi-update firmware in a few days, then in a few weeks as a Raspbian package).

@P33M
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P33M commented Apr 27, 2017

I've got a fix for the first instance of the problem (high latency when requesting data on an open() and read() call) and I think I'm now seeing

So if I open the port and I'm able to communicate, everything goes fine until I close the port; but if the first command fails, then the communication keeps failing until I close the port.

in the test program, i.e. you open the port, send a command, the server sees the command and responds (via the USB uart) but you never get any data out of your read() call.

This seems to be happening once every 40-50 times the port is opened, rather than the deterministic behaviour seen previously.

Edit: It appears that in this specific failure mode, the first data received is dropped on the floor. If I subsequently do "echo steve > /dev/ttyAMA0", "steve" pops out in the USB test program and subsequent reads return data, but I never see the first response from the remote server.

P33M pushed a commit to P33M/linux that referenced this issue Apr 27, 2017
If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes raspberrypi#1709
@P33M
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P33M commented Apr 28, 2017

I've seen an instance of the correct response being sent across the wire after the first message is sent after an open(), but the first URB returned to usb-serial after an open() is just the FTDI 2-byte status packet. Further investigation required.

Edit: the failure still occurs even if nak_holdoff=0.

@P33M P33M reopened this Apr 28, 2017
popcornmix added a commit to raspberrypi/firmware that referenced this issue Apr 28, 2017
kernel: dwc_otg: make nak_holdoff work as intended with empty queues
See: raspberrypi/linux#1709

kernel: vc4_fkms: Apply firmware overscan offset to hardware cursor
See: raspberrypi/linux#1960
popcornmix added a commit to Hexxeh/rpi-firmware that referenced this issue Apr 28, 2017
kernel: dwc_otg: make nak_holdoff work as intended with empty queues
See: raspberrypi/linux#1709

kernel: vc4_fkms: Apply firmware overscan offset to hardware cursor
See: raspberrypi/linux#1960
@P33M
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P33M commented May 2, 2017

I believe I now have a fix for the failure on open().

The issue was caused by
a) a dequeue being issued to an endpoint that was in the middle of a FIQ-accelerated transfer
b) the last transfer to the endpoint returned data
c) the first transfer data from endpoint on the next open() consisted of both 2-byte status and valid data

In b) the driver didn't save the endpoint data toggle state correctly. Thus the next transfer in c) would get dropped on the floor, and if it contained actual serial port data then that data got lost.

I also found an issue regarding uninitialised packet counts in the host channel structure, where stale hc->start_pkt_count values would result in bogus lengths being passed back to the ftdi_sio driver on transfers that had data toggle errors.

The test program now runs for >10mins with no errors. I will create a PR shortly.

popcornmix added a commit that referenced this issue Sep 10, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
popcornmix added a commit that referenced this issue Sep 12, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
popcornmix added a commit that referenced this issue Sep 16, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 2, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 2, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
popcornmix added a commit that referenced this issue Oct 7, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 10, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 10, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
popcornmix added a commit that referenced this issue Oct 14, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 14, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 17, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 21, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 23, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Oct 28, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 1, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 5, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 6, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 8, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 11, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 18, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 18, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 18, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 25, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Nov 25, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 7, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 9, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 10, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 16, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 16, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
popcornmix added a commit that referenced this issue Dec 20, 2024
Signed-off-by: popcornmix <popcornmix@gmail.com>

usb: dwc: fix lockdep false positive

Signed-off-by: Kari Suvanto <karis79@gmail.com>

usb: dwc: fix inconsistent lock state

Signed-off-by: Kari Suvanto <karis79@gmail.com>

Add FIQ patch to dwc_otg driver. Enable with dwc_otg.fiq_fix_enable=1. Should give about 10% more ARM performance.
Thanks to Gordon and Costas

Avoid dynamic memory allocation for channel lock in USB driver. Thanks ddv2005.

Add NAK holdoff scheme. Enabled by default, disable with dwc_otg.nak_holdoff_enable=0. Thanks gsh

Make sure we wait for the reset to finish

dwc_otg: fix bug in dwc_otg_hcd.c resulting in silent kernel
	 memory corruption, escalating to OOPS under high USB load.

dwc_otg: Fix unsafe access of QTD during URB enqueue

In dwc_otg_hcd_urb_enqueue during qtd creation, it was possible that the
transaction could complete almost immediately after the qtd was assigned
to a host channel during URB enqueue, which meant the qtd pointer was no
longer valid having been completed and removed. Usually, this resulted in
an OOPS during URB submission. By predetermining whether transactions
need to be queued or not, this unsafe pointer access is avoided.

This bug was only evident on the Pi model A where a device was attached
that had no periodic endpoints (e.g. USB pendrive or some wlan devices).

dwc_otg: Fix incorrect URB allocation error handling

If the memory allocation for a dwc_otg_urb failed, the kernel would OOPS
because for some reason a member of the *unallocated* struct was set to
zero. Error handling changed to fail correctly.

dwc_otg: fix potential use-after-free case in interrupt handler

If a transaction had previously aborted, certain interrupts are
enabled to track error counts and reset where necessary. On IN
endpoints the host generates an ACK interrupt near-simultaneously
with completion of transfer. In the case where this transfer had
previously had an error, this results in a use-after-free on
the QTD memory space with a 1-byte length being overwritten to
0x00.

dwc_otg: add handling of SPLIT transaction data toggle errors

Previously a data toggle error on packets from a USB1.1 device behind
a TT would result in the Pi locking up as the driver never handled
the associated interrupt. Patch adds basic retry mechanism and
interrupt acknowledgement to cater for either a chance toggle error or
for devices that have a broken initial toggle state (FT8U232/FT232BM).

dwc_otg: implement tasklet for returning URBs to usbcore hcd layer

The dwc_otg driver interrupt handler for transfer completion will spend
a very long time with interrupts disabled when a URB is completed -
this is because usb_hcd_giveback_urb is called from within the handler
which for a USB device driver with complicated processing (e.g. webcam)
will take an exorbitant amount of time to complete. This results in
missed completion interrupts for other USB packets which lead to them
being dropped due to microframe overruns.

This patch splits returning the URB to the usb hcd layer into a
high-priority tasklet. This will have most benefit for isochronous IN
transfers but will also have incidental benefit where multiple periodic
devices are active at once.

dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.

dwc_otg: Call usb_hcd_unlink_urb_from_ep with lock held in completion handler

usb_hcd_unlink_urb_from_ep must be called with the HCD lock held.  Calling it
asynchronously in the tasklet was not safe (regression in
c4564d4).

This change unlinks it from the endpoint prior to queueing it for handling in
the tasklet, and also adds a check to ensure the urb is OK to be unlinked
before doing so.

NULL pointer dereference kernel oopses had been observed in usb_hcd_giveback_urb
when a USB device was unplugged/replugged during data transfer.  This effect
was reproduced using automated USB port power control, hundreds of replug
events were performed during active transfers to confirm that the problem was
eliminated.

USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux

dwc_otg: fix device attributes and avoid kernel warnings on boot

dcw_otg: avoid logging function that can cause panics

See: raspberrypi/firmware#21
Thanks to cleverca22 for fix

dwc_otg: mask correct interrupts after transaction error recovery

The dwc_otg driver will unmask certain interrupts on a transaction
that previously halted in the error state in order to reset the
QTD error count. The various fine-grained interrupt handlers do not
consider that other interrupts besides themselves were unmasked.

By disabling the two other interrupts only ever enabled in DMA mode
for this purpose, we can avoid unnecessary function calls in the
IRQ handler. This will also prevent an unneccesary FIQ interrupt
from being generated if the FIQ is enabled.

dwc_otg: fiq: prevent FIQ thrash and incorrect state passing to IRQ

In the case of a transaction to a device that had previously aborted
due to an error, several interrupts are enabled to reset the error
count when a device responds. This has the side-effect of making the
FIQ thrash because the hardware will generate multiple instances of
a NAK on an IN bulk/interrupt endpoint and multiple instances of ACK
on an OUT bulk/interrupt endpoint. Make the FIQ mask and clear the
associated interrupts.

Additionally, on non-split transactions make sure that only unmasked
interrupts are cleared. This caused a hard-to-trigger but serious
race condition when you had the combination of an endpoint awaiting
error recovery and a transaction completed on an endpoint - due to
the sequencing and timing of interrupts generated by the dwc_otg core,
it was possible to confuse the IRQ handler.

Fix function tracing

dwc_otg: whitespace cleanup in dwc_otg_urb_enqueue

dwc_otg: prevent OOPSes during device disconnects

The dwc_otg_urb_enqueue function is thread-unsafe. In particular the
access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and
friends does not occur within a critical section and so if a device
was unplugged during activity there was a high chance that the
usbcore hub_thread would try to disable the endpoint with partially-
formed entries in the URB queue. This would result in BUG() or null
pointer dereferences.

Fix so that access of urb->hcpriv, enqueuing to the hardware and
adding to usbcore endpoint URB lists is contained within a single
critical section.

dwc_otg: prevent BUG() in TT allocation if hub address is > 16

A fixed-size array is used to track TT allocation. This was
previously set to 16 which caused a crash because
dwc_otg_hcd_allocate_port would read past the end of the array.

This was hit if a hub was plugged in which enumerated as addr > 16,
due to previous device resets or unplugs.

Also add #ifdef FIQ_DEBUG around hcd->hub_port_alloc[], which grows
to a large size if 128 hub addresses are supported. This field is
for debug only for tracking which frame an allocate happened in.

dwc_otg: make channel halts with unknown state less damaging

If the IRQ received a channel halt interrupt through the FIQ
with no other bits set, the IRQ would not release the host
channel and never complete the URB.

Add catchall handling to treat as a transaction error and retry.

dwc_otg: fiq_split: use TTs with more granularity

This fixes certain issues with split transaction scheduling.

- Isochronous multi-packet OUT transactions now hog the TT until
  they are completed - this prevents hubs aborting transactions
  if they get a periodic start-split out-of-order
- Don't perform TT allocation on non-periodic endpoints - this
  allows simultaneous use of the TT's bulk/control and periodic
  transaction buffers

This commit will mainly affect USB audio playback.

dwc_otg: fix potential sleep while atomic during urb enqueue

Fixes a regression introduced with eb1b482. Kmalloc called from
dwc_otg_hcd_qtd_add / dwc_otg_hcd_qtd_create did not always have
the GPF_ATOMIC flag set. Force this flag when inside the larger
critical section.

dwc_otg: make fiq_split_enable imply fiq_fix_enable

Failing to set up the FIQ correctly would result in
"IRQ 32: nobody cared" errors in dmesg.

dwc_otg: prevent crashes on host port disconnects

Fix several issues resulting in crashes or inconsistent state
if a Model A root port was disconnected.

- Clean up queue heads properly in kill_urbs_in_qh_list by
  removing the empty QHs from the schedule lists
- Set the halt status properly to prevent IRQ handlers from
  using freed memory
- Add fiq_split related cleanup for saved registers
- Make microframe scheduling reclaim host channels if
  active during a disconnect
- Abort URBs with -ESHUTDOWN status response, informing
  device drivers so they respond in a more correct fashion
  and don't try to resubmit URBs
- Prevent IRQ handlers from attempting to handle channel
  interrupts if the associated URB was dequeued (and the
  driver state was cleared)

dwc_otg: prevent leaking URBs during enqueue

A dwc_otg_urb would get leaked if the HCD enqueue function
failed for any reason. Free the URB at the appropriate points.

dwc_otg: Enable NAK holdoff for control split transactions

Certain low-speed devices take a very long time to complete a
data or status stage of a control transaction, producing NAK
responses until they complete internal processing - the USB2.0
spec limit is up to 500mS. This causes the same type of interrupt
storm as seen with USB-serial dongles prior to c8edb23.

In certain circumstances, usually while booting, this interrupt
storm could cause SD card timeouts.

dwc_otg: Fix for occasional lockup on boot when doing a USB reset

dwc_otg: Don't issue traffic to LS devices in FS mode

Issuing low-speed packets when the root port is in full-speed mode
causes the root port to stop responding. Explicitly fail when
enqueuing URBs to a LS endpoint on a FS bus.

Fix ARM architecture issue with local_irq_restore()

If local_fiq_enable() is called before a local_irq_restore(flags) where
the flags variable has the F bit set, the FIQ will be erroneously disabled.

Fixup arch_local_irq_restore to avoid trampling the F bit in CPSR.

Also fix some of the hacks previously implemented for previous dwc_otg
incarnations.

dwc_otg: fiq_fsm: Base commit for driver rewrite

This commit removes the previous FIQ fixes entirely and adds fiq_fsm.

This rewrite features much more complete support for split transactions
and takes into account several OTG hardware bugs. High-speed
isochronous transactions are also capable of being performed by fiq_fsm.

All driver options have been removed and replaced with:
  - dwc_otg.fiq_enable (bool)
  - dwc_otg.fiq_fsm_enable (bool)
  - dwc_otg.fiq_fsm_mask (bitmask)
  - dwc_otg.nak_holdoff (unsigned int)

Defaults are specified such that fiq_fsm behaves similarly to the
previously implemented FIQ fixes.

fiq_fsm: Push error recovery into the FIQ when fiq_fsm is used

If the transfer associated with a QTD failed due to a bus error, the HCD
would retry the transfer up to 3 times (implementing the USB2.0
three-strikes retry in software).

Due to the masking mechanism used by fiq_fsm, it is only possible to pass
a single interrupt through to the HCD per-transfer.

In this instance host channels would fall off the radar because the error
reset would function, but the subsequent channel halt would be lost.

Push the error count reset into the FIQ handler.

fiq_fsm: Implement timeout mechanism

For full-speed endpoints with a large packet size, interrupt latency
runs the risk of the FIQ starting a transaction too late in a full-speed
frame. If the device is still transmitting data when EOF2 for the
downstream frame occurs, the hub will disable the port. This change is
not reflected in the hub status endpoint and the device becomes
unresponsive.

Prevent high-bandwidth transactions from being started too late in a
frame. The mechanism is not guaranteed: a combination of bit stuffing
and hub latency may still result in a device overrunning.

fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

dwc_otg: Return full-speed frame numbers in HS mode

The frame counter increments on every *microframe* in high-speed mode.
Most device drivers expect this number to be in full-speed frames - this
caused considerable confusion to e.g. snd_usb_audio which uses the
frame counter to estimate the number of samples played.

fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.

fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.

fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.

fiq_fsm: enable by default

fiq_fsm: fix dequeues for non-periodic split transactions

If a dequeue happened between the SSPLIT and CSPLIT phases of the
transaction, the HCD would never receive an interrupt.

fiq_fsm: Disable by default

fiq_fsm: Handle HC babble errors

The HCTSIZ transfer size field raises a babble interrupt if
the counter wraps. Handle the resulting interrupt in this case.

dwc_otg: fix interrupt registration for fiq_enable=0

Additionally make the module parameter conditional for wherever
hcd->fiq_state is touched.

fiq_fsm: Enable by default

dwc_otg: Fix various issues with root port and transaction errors

Process the host port interrupts correctly (and don't trample them).
Root port hotplug now functional again.

Fix a few thinkos with the transaction error passthrough for fiq_fsm.

fiq_fsm: Implement hack for Split Interrupt transactions

Hubs aren't too picky about which endpoint we send Control type split
transactions to. By treating Interrupt transfers as Control, it is
possible to use the non-periodic queue in the OTG core as well as the
non-periodic FIFOs in the hub itself. This massively reduces the
microframe exclusivity/contention that periodic split transactions
otherwise have to enforce.

It goes without saying that this is a fairly egregious USB specification
violation, but it works.

Original idea by Hans Petter Selasky @ FreeBSD.org.

dwc_otg: FIQ support on SMP. Set up FIQ stack and handler on Core 0 only.

dwc_otg: introduce fiq_fsm_spin(un|)lock()

SMP safety for the FIQ relies on register read-modify write cycles being
completed in the correct order. Several places in the DWC code modify
registers also touched by the FIQ. Protect these by a bare-bones lock
mechanism.

This also makes it possible to run the FIQ and IRQ handlers on different
cores.

fiq_fsm: fix build on bcm2708 and bcm2709 platforms

dwc_otg: put some barriers back where they should be for UP

bcm2709/dwc_otg: Setup FIQ on core 1 if >1 core active

dwc_otg: fixup read-modify-write in critical paths

Be more careful about read-modify-write on registers that the FIQ
also touches.

Guard fiq_fsm_spin_lock with fiq_enable check

fiq_fsm: Falling out of the state machine isn't fatal

This edge case can be hit if the port is disabled while the FIQ is
in the middle of a transaction. Make the effects less severe.

Also get rid of the useless return value.

squash: dwc_otg: Allow to build without SMP

usb: core: make overcurrent messages more prominent

Hub overcurrent messages are more serious than "debug". Increase loglevel.

usb: dwc_otg: Don't use dma_to_virt()

Commit 6ce0d20 changes dma_to_virt() which breaks this driver.
Open code the old dma_to_virt() implementation to work around this.

Limit the use of __bus_to_virt() to cases where transfer_buffer_length
is set and transfer_buffer is not set. This is done to increase the
chance that this driver will also work on ARCH_BCM2835.

transfer_buffer should not be NULL if the length is set, but the
comment in the code indicates that there are situations where this
might happen. drivers/usb/isp1760/isp1760-hcd.c also has a similar
comment pointing to a possible: 'usb storage / SCSI bug'.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Fix crash when fiq_enable=0

dwc_otg: fiq_fsm: Make high-speed isochronous strided transfers work properly

Certain low-bandwidth high-speed USB devices (specialist audio devices,
compressed-frame webcams) have packet intervals > 1 microframe.

Stride these transfers in the FIQ by using the start-of-frame interrupt
to restart the channel at the right time.

dwc_otg: Force host mode to fix incorrect compute module boards

dwc_otg: Add ARCH_BCM2835 support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Simplify FIQ irq number code

Dropping ATAGS means we can simplify the FIQ irq number code.
Also add error checking on the returned irq number.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: Remove duplicate gadget probe/unregister function

dwc_otg: Properly set the HFIR

Douglas Anderson reported:

According to the most up to date version of the dwc2 databook, the FRINT
field of the HFIR register should be programmed to:
* 125 us * (PHY clock freq for HS) - 1
* 1000 us * (PHY clock freq for FS/LS) - 1

This is opposed to older versions of the doc that claimed it should be:
* 125 us * (PHY clock freq for HS)
* 1000 us * (PHY clock freq for FS/LS)

and reported lower timing jitter on a USB analyser

dcw_otg: trim xfer length when buffer larger than allocated size is received

dwc_otg: Don't free qh align buffers in atomic context

dwc_otg: Enable the hack for Split Interrupt transactions by default

dwc_otg.fiq_fsm_mask=0xF has long been a suggestion for users with audio stutters or other USB bandwidth issues.
So far we are aware of many success stories but no failure caused by this setting.
Make it a default to learn more.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=70437

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: Use kzalloc when suitable

dwc_otg: Pass struct device to dma_alloc*()

This makes it possible to get the bus address from Device Tree.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dwc_otg: fix summarize urb->actual_length for isochronous transfers

Kernel does not copy input data of ISO transfers to userspace
if actual_length is set only in ISO transfers and not summarized
in urb->actual_length. Fixes #903

fiq_fsm: Use correct states when starting isoc OUT transfers

In fiq_fsm_start_next_periodic() if an isochronous OUT transfer
was selected, no regard was given as to whether this was a single-packet
transfer or a multi-packet staged transfer.

For single-packet transfers, this had the effect of repeatedly sending
OUT packets with bogus data and lengths.

Eventually if the channel was repeatedly enabled enough times, this
would lock up the OTG core and no further bus transfers would happen.

Set the FSM state up properly if we select a single-packet transfer.

Fixes #1842

dwc_otg: make nak_holdoff work as intended with empty queues

If URBs reading from non-periodic split endpoints were dequeued and
the last transfer from the endpoint was a NAK handshake, the resulting
qh->nak_frame value was stale which would result in unnecessarily long
polling intervals for the first subsequent transfer with a fresh URB.

Fixup qh->nak_frame in dwc_otg_hcd_urb_dequeue and also guard against
a case where a single URB is submitted to the endpoint, a NAK was
received on the transfer immediately prior to receiving data and the
device subsequently resubmits another URB past the qh->nak_frame interval.

Fixes #1709

dwc_otg: fix split transaction data toggle handling around dequeues

See #1709

Fix several issues regarding endpoint state when URBs are dequeued
- If the HCD is disconnected, flush FIQ-enabled channels properly
- Save the data toggle state for bulk endpoints if the last transfer
  from an endpoint where URBs were dequeued returned a data packet
- Reset hc->start_pkt_count properly in assign_and_init_hc()

dwc_otg: fix several potential crash sources

On root port disconnect events, the host driver state is cleared and
in-progress host channels are forcibly stopped. This doesn't play
well with the FIQ running in the background, so:
- Guard the disconnect callback with both the host spinlock and FIQ
  spinlock
- Move qtd dereference in dwc_otg_handle_hc_fsm() after the early-out
  so we don't dereference a qtd that has gone away
- Turn catch-all BUG()s in dwc_otg_handle_hc_fsm() into warnings.

dwc_otg: delete hcd->channel_lock

The lock serves no purpose as it is only held while the HCD spinlock
is already being held.

dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

dwcotg: Allow to build without FIQ on ARM64

Signed-off-by: popcornmix <popcornmix@gmail.com>

dwc_otg: make periodic scheduling behave properly for FS buses

If the root port is in full-speed mode, transfer times at 12mbit/s
would be calculated but matched against high-speed quotas.

Reinitialise hcd->frame_usecs[i] on each port enable event so that
full-speed bandwidth can be tracked sensibly.

Also, don't bother using the FIQ for transfers when in full-speed
mode - at the slower bus speed, interrupt frequency is reduced by
an order of magnitude.

Related issue: #2020

dwc_otg: fiq_fsm: Make isochronous compatibility checks work properly

Get rid of the spammy printk and local pointer mangling.
Also, there is a nominal benefit for using fiq_fsm for isochronous
transfers in FS mode (~1.1k IRQs per second vs 2.1k IRQs per second)
so remove the root port speed check.

dwc_otg: add module parameter int_ep_interval_min

Add a module parameter (defaulting to ignored) that clamps the polling rate
of high-speed Interrupt endpoints to a minimum microframe interval.

The parameter is modifiable at runtime as it is used when activating new
endpoints (such as on device connect).

dwc_otg: fiq_fsm: Add non-periodic TT exclusivity constraints

Certain hub types do not discriminate between pipe direction (IN or OUT)
when considering non-periodic transfers. Therefore these hubs get confused
if multiple transfers are issued in different directions with the same
device address and endpoint number.

Constrain queuing non-periodic split transactions so they are performed
serially in such cases.

Related: #2024

dwc_otg: Fixup change to DRIVER_ATTR interface

dwc_otg: Fix compilation warnings

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

USB_DWCOTG: Disable building dwc_otg as a module (#2265)

When dwc_otg is built as a module, build will fail with the following
error:

ERROR: "DWC_TASK_HI_SCHEDULE" [drivers/usb/host/dwc_otg/dwc_otg.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1199: recipe for target 'modules' failed
make: *** [modules] Error 2

Even if the error is solved by including the missing
DWC_TASK_HI_SCHEDULE function, the kernel will panic when loading
dwc_otg.

As a workaround, simply prevent user from building dwc_otg as a module
as the current kernel does not support it.

See: #2258

Signed-off-by: Malik Olivier Boussejra <malik@boussejra.com>

dwc_otg: New timer API

dwc_otg: Fix removed ACCESS_ONCE->READ_ONCE

dwc_otg: don't unconditionally force host mode in dwc_otg_cil_init()

Add the ability to disable force_host_mode for those that want to use
dwc_otg in both device and host modes.

dwc_otg: Fix a regression when dequeueing isochronous transfers

In 282bed9 (dwc_otg: make nak_holdoff work as intended with empty queues)
the dequeue mechanism was changed to leave FIQ-enabled transfers to run
to completion - to avoid leaving hub TT buffers with stale packets lying
around.

This broke FIQ-accelerated isochronous transfers, as this then meant that
dozens of transfers were performed after the dequeue function returned.

Restore the state machine fence for isochronous transfers.

fiq_fsm: rewind DMA pointer for OUT transactions that fail (#2288)

See: #2140

dwc_otg: add smp_mb() to prevent driver state corruption on boot

Occasional crashes have been seen where the FIQ code dereferences
invalid/random pointers immediately after being set up, leading to
panic on boot.

The crash occurs as the FIQ code races against hcd_init_fiq() and
the hcd_init_fiq() code races against the outstanding memory stores
from dwc_otg_hcd_init(). Use explicit barriers after touching
driver state.

usb: dwc_otg: fix memory corruption in dwc_otg driver

[Upstream commit 51b1b64]

The move from the staging tree to the main tree exposed a
longstanding memory corruption bug in the dwc2 driver. The
reordering of the driver initialization caused the dwc2 driver
to corrupt the initialization data of the sdhci driver on the
Raspberry Pi platform, which made the bug show up.

The error is in calling to_usb_device(hsotg->dev), since ->dev
is not a member of struct usb_device. The easiest fix is to
just remove the offending code, since it is not really needed.

Thanks to Stephen Warren for tracking down the cause of this.

Reported-by: Andre Heider <a.heider@gmail.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[lukas: port from upstream dwc2 to out-of-tree dwc_otg driver]
Signed-off-by: Lukas Wunner <lukas@wunner.de>

usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

dwc_otg: fiq_fsm: fix incorrect DMA register offset calculation

Rationalise the offset and update all call sites.

Fixes #2408

dwc_otg: fix bug with port_addr assignment for single-TT hubs

See #2734

The "Hub Port" field in the split transaction packet was always set
to 1 for single-TT hubs. The majority of single-TT hub products
apparently ignore this field and broadcast to all downstream enabled
ports, which masked the issue. A subset of hub devices apparently
need the port number to be exact or split transactions will fail.

usb: dwc_otg: Clean up build warnings on 64bit kernels

No functional changes. Almost all are changes to logging lines.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

usb: dwc_otg: Use dma allocation for mphi dummy_send buffer

The FIQ driver used a kzalloc'ed buffer for dummy_send,
passing a kernel virtual address to the hardware block.
The buffer is only ever used for a dummy read, so it
should be harmless, but there is the chance that it will
cause exceptions.

Use a dma allocation so that we have a genuine bus address,
and read from that.
Free the allocation when done for good measure.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

dwc_otg: only do_split when we actually need to do a split

The previous test would fail if the root port was in fullspeed mode
and there was a hub between the FS device and the root port. While
the transfer worked, the schedule mangling performed for high-speed
split transfers would break leading to an 8ms polling interval.

dwc_otg: fix locking around dequeueing and killing URBs

kill_urbs_in_qh_list() is practically only ever called with the fiq lock
already held, so don't spinlock twice in the case where we need to cancel
an isochronous transfer.

Also fix up a case where the global interrupt register could be read with
the fiq lock not held.

Fixes the deadlock seen in #2907

ARM64/DWC_OTG: Port dwc_otg driver to ARM64

In ARM64, the FIQ mechanism used by this driver is not current
implemented.   As a workaround, reqular IRQ is used instead
of FIQ.

In a separate change, the IRQ-CPU mapping is round robined
on ARM64 to increase concurrency and allow multiple interrupts
to be serviced at a time.  This reduces the need for FIQ.

Tests Run:

This mechanism is most likely to break when multiple USB devices
are attached at the same time.  So the system was tested under
stress.

Devices:

1. USB Speakers playing back a FLAC audio through VLC
   at 96KHz.(Higher then typically, but supported on my speakers).

2. sftp transferring large files through the buildin ethernet
   connection which is connected through USB.

3. Keyboard and mouse attached and being used.

Although I do occasionally hear some glitches, the music seems to
play quite well.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>

usb: dwc_otg: Clean up interrupt claiming code

The FIQ/IRQ interrupt number identification code is scattered through
the dwc_otg driver. Rationalise it, simplifying the code and solving
an existing issue.

See: #2612

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: Choose appropriate IRQ handover strategy

2711 has no MPHI peripheral, but the ARM Control block can fake
interrupts. Use the size of the DTB "mphi" reg block to determine
which is required.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

usb: host: dwc_otg: fix compiling in separate directory

The dwc_otg Makefile does not respect the O=path argument correctly:
include paths in CFLAGS are given relatively to object path, not source
path. Compiling in a separate directory yields #include errors.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

dwc_otg: use align_buf for small IN control transfers (#3150)

The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.

Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.

In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.

See: #3148

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: Declare DMA capability with HCD_DMA flag

Following [1], USB controllers have to declare DMA capabilities in
order for them to be used by adding the HCD_DMA flag to their hc_driver
struct.

[1] 7b81cb6 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

dwc_otg: checking the urb->transfer_buffer too early (#3332)

After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't
work well on Pi2/3 boards with 1G physical ram. Users experience
the failure when copying a file of 600M size to the USB stick. And
at the same time, the dmesg shows:
usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg
sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0

When this happens, the sg_buf sent to the driver is located in the
highmem region, the usb_sg_init() in the core/message.c will leave
transfer_buffer to NULL if the sg_buf is in highmem, but in the
dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer
is NULL.

The driver can handle the situation of buffer to be NULL, if it is in
DMA mode, it will convert an address from transfer_dma.

But if the conversion fails or it is in the PIO mode, we should check
buffer and return -EINVAL if it is NULL.

BugLink: https://bugs.launchpad.net/bugs/1852510
Signed-off-by: Hui Wang <hui.wang@canonical.com>

dwc_otg: constrain endpoint max packet and transfer size on split IN

The hcd would unconditionally set the transfer length to the endpoint
packet size for non-isoc IN transfers. If the remaining buffer length
was less than the length of returned data, random memory would get
scribbled over, with bad effects if it crossed a page boundary.

Force a babble error if this happens by limiting the max transfer size
to the available buffer space. DMA will stop writing to memory on a
babble condition.

The hardware expects xfersize to be an integer multiple of maxpacket
size, so override hcchar.b.mps as well.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: pause when cancelling split transactions

Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
which may be freed immediately after the dequeue call returns. Block until
we know the transfer is complete.

A similar delay is needed when cleaning up disconnects, as the FIQ could
have started a periodic transfer in the previous microframe to the one
that triggered a disconnect.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: fiq_fsm: add a barrier on entry into FIQ handler(s)

On BCM2835, there is no hardware guarantee that multiple outstanding
reads to different peripherals will complete in-order. The FIQ code
uses peripheral reads without barriers for performance, so in the case
where a read to a slow peripheral was issued immediately prior to FIQ
entry, the first peripheral read that the FIQ did could end up with
wrong read data returned.

Add dsb(sy) on entry so that all outstanding reads are retired.

The FIQ only issues reads to the dwc_otg core, so per-read barriers
in the handler itself are not required.

On BCM2836 and BCM2837 the barrier is not strictly required due to
differences in how the peripheral bus is implemented, but having
arch-specific handlers that introduce different latencies is risky.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>

dwc_otg: whitelist_table is now productlist_table

dwc_otg: initialise sched_frame for periodic QHs that were parked

If a periodic QH has no remaining QTDs, then it is removed from all
periodic schedules. When re-adding, initialise the sched_frame and
start_split_frame from the current value of the frame counter.

See https://bugs.launchpad.net/raspbian/+bug/1819560
and
 #3883

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Minimise header and fix build warnings

Delete a large amount of unused declaration from "usb.h", some of which
were causing build warnings, and get the module building cleanly.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc-otg: fix clang -Wignored-attributes warning

warning: attribute declaration must precede definition

dwc-otg: fix clang -Wsometimes-uninitialized warning

warning: variable 'retval' is used uninitialized whenever 'if' condition is false

dwc-otg: fix clang -Wpointer-bool-conversion warning

warning: address of array 'desc->wMaxPacketSize' will always evaluate to 'true'

The wMaxPacketSize field is actually a two element array which content should
be accessed via the UGETW macro.

dwc_otg: fix an undeclared variable
Replace an undeclared variable used by DWC_DEBUGPL with the real endpoint address. DWC_DEBUGPL does nothing with DEBUG undefined so it did not go wrong before.
Signed-off-by: Zixuan Wang <wangzixuan@sjtu.edu.cn>

dwc_otg: Update NetBSD usb.h header licence

NetBSD have changed their licensing requirements such that the 2-clause
licence is preferred. Update usb.h in the downstream dwc_otg code
accordingly.

See https://www.netbsd.org/about/redistribution.html for more
information.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

dwc_otg: pay attention to qh->interval when rescheduling periodic queues

A regression introduced in #3887
meant that if the newly scheduled transfer immediately returned data, and
the driver resubmitted a single URB after every transfer, then the effective
polling interval would end up being approx 1ms.

Use the larger of SCHEDULE_SLOP or the configured endpoint interval.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: Fix fallthrough warnings

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers: usb: dwc_otg: fix reference passing when checking bandwidth

The pointer (struct usb_host_endpoint *)->hcpriv should contain a
reference to dwc_otg_qh_t if the driver has already seen a URB submitted
to this endpoint.

It then checks whether the qh exists and is already in a schedule in
order to decide whether to allocate periodic bandwidth or not. Passing a
pointer to an offset inside of struct usb_host_endpoint instead of just
the pointer means it dereferences bogus addresses.

Rationalise (delete) a variable while we're at it.

See #5189

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

drivers: dwc_otg: stop GCC from patching FIQ functions

Configuring GCC to use task stack protector canaries means it will
insert calls to check functions in FIQ code. This is bad, as a) the
FIQ's stack is banked and b) the failure invokes __stack_chk_fail which
eventually tries to call printk(). Printing to the console inside the
FIQ is generally fatal.

Add CFLAGS to stop this happening in FIQ code.

Also catch one function where notrace wasn't specified.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

dwc_otg: Avoid the use of align_buf for short packets

Recent kernels (from 6.5) fail to boot on Pi0-3.

This has been tracked down to the call to:
ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);

returning garbage in hubstatus (it gets the uninitialised contents of
a kmalloc buffer that is not overwritten as expected).

As we don't have strong evidence that this code path has ever worked,
and it is causing a clear problem currently, lets disable it to
allow wider use of newer kernels.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

drivers: dwc_otg: use C11 style variable array declarations

The kernel C standard changed in 5.18.

Remove a layer of indirection around the FIQ bounce buffers, be consistent
with pointers to FIQ bounce buffers, and remove open-coded 32-bit clamping
of DMA addresses.

Also remove a pointless fiq_state initialisation loop.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
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