USB disconnects and reconnects cause kernel panics #1272
Description
I'm experiencing an infrequent crash, which has a number of reported errors:
- Internal error: Oops: 5 [var->green.length may be left uninitialized #1] ARM
- Kernel Panic - Not syncing: Fatal exception in interrupt
- Internal error: Oops: 805 [var->green.length may be left uninitialized #1] ARM
Other common messages seen are
"Unable to handle kernel paging request at virtual address 0x......"
In normal use, this seems to occur because one or USB devices have spontaneously disconnected and reconnected. The root cause of this is still unknown (but outside the scope of this issue)
However I am able to make the OS crash easily by running the following script to force USB devices to reconnect:
echo 0 > /sys/bus/platform/drivers/dwc_otg/20980000.usb/buspower
echo 1 > /sys/bus/platform/drivers/dwc_otg/20980000.usb/buspower
I have a second script which runs this in a loop (with a "sleep 2" in between each cycle), and this results in a kernel panic after a few minutes.
I'm not running any other applications at the time, and this is at the moment just a fresh install of Raspbian Jessie Lite.
I'm using a RPi B+ , with the following USB connections:
Port 2 - keyboard
Port 4 - Sierra Wireless 3g modem
Port 5 - Audio card
I've attached the output of lsusb -v, lsusb.txt
I initially thought it might be related to one of the USB devices, but I tried unplugging the modem and audio card but the problem still occurred. Interestingly, I have never seen the crash if I don't have any USB devices connected.
I originally noticed the problem on Raspbian Jessie Lite, kernel 4.1.13+. I also tried running rpi-update to update the kernel to 4.1.16+, but the problem persisted.
I'm not sure how to get the output of the kernel dumps, after the problem occurs, I reset the unit and there's no kernel info in the logs. Some photos are here: 
What other information can I provide to help resolve the issue?