From 4949abede86b7fd88930ff6fae51d02b77e71d82 Mon Sep 17 00:00:00 2001 From: Jonathan Bell Date: Thu, 11 Jul 2019 17:55:43 +0100 Subject: [PATCH] xhci: add quirk for host controllers that don't update endpoint DCS Seen on a VLI VL805 PCIe to USB controller. For non-stream endpoints at least, if the xHC halts on a particular TRB due to an error then the DCS field in the Out Endpoint Context maintained by the hardware is not updated with the current cycle state. Using the quirk XHCI_EP_CTX_BROKEN_DCS and instead fetch the DCS bit from the TRB that the xHC stopped on. See: https://github.com/raspberrypi/linux/issues/3060 Signed-off-by: Jonathan Bell --- drivers/usb/host/xhci-pci.c | 4 +++- drivers/usb/host/xhci-ring.c | 26 ++++++++++++++++++++++++++ drivers/usb/host/xhci.h | 1 + 3 files changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 5bbccc9a0179ff..96e37f60c7c2ff 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -270,8 +270,10 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) pdev->device == 0x3432) xhci->quirks |= XHCI_BROKEN_STREAMS; - if (pdev->vendor == PCI_VENDOR_ID_VIA && pdev->device == 0x3483) + if (pdev->vendor == PCI_VENDOR_ID_VIA && pdev->device == 0x3483) { xhci->quirks |= XHCI_LPM_SUPPORT; + xhci->quirks |= XHCI_EP_CTX_BROKEN_DCS; + } if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA && pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index ce38076901e250..61690f848adeb7 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -560,8 +560,11 @@ static int xhci_move_dequeue_past_td(struct xhci_hcd *xhci, struct xhci_ring *ep_ring; struct xhci_command *cmd; struct xhci_segment *new_seg; + struct xhci_segment *halted_seg = NULL; union xhci_trb *new_deq; int new_cycle; + union xhci_trb *halted_trb; + int index = 0; dma_addr_t addr; u64 hw_dequeue; bool cycle_found = false; @@ -601,6 +604,29 @@ static int xhci_move_dequeue_past_td(struct xhci_hcd *xhci, new_deq = ep_ring->dequeue; new_cycle = hw_dequeue & 0x1; + /* + * Quirk: xHC write-back of the DCS field in the hardware dequeue + * pointer is wrong - use the cycle state of the TRB pointed to by + * the dequeue pointer. + */ + if (xhci->quirks & XHCI_EP_CTX_BROKEN_DCS && + !(ep->ep_state & EP_HAS_STREAMS)) + halted_seg = trb_in_td(xhci, cur_td->start_seg, + cur_td->first_trb, cur_td->last_trb, + hw_dequeue & ~0xf, false); + if (halted_seg) { + index = ((dma_addr_t)(hw_dequeue & ~0xf) - halted_seg->dma) / + sizeof(*halted_trb); + halted_trb = &halted_seg->trbs[index]; + state->new_cycle_state = halted_trb->generic.field[3] & 0x1; + xhci_dbg(xhci, "Endpoint DCS = %d TRB index = %d cycle = %d\n", + (u8)(hw_dequeue & 0x1), index, + state->new_cycle_state); + } else { + state->new_cycle_state = hw_dequeue & 0x1; + } + state->stream_id = stream_id; + /* * We want to find the pointer, segment and cycle state of the new trb * (the one after current TD's last_trb). We know the cycle state at diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index ca822ad3b65b0f..9cdef05a2d77e7 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1892,6 +1892,7 @@ struct xhci_hcd { #define XHCI_DISABLE_SPARSE BIT_ULL(38) #define XHCI_SG_TRB_CACHE_SIZE_QUIRK BIT_ULL(39) #define XHCI_NO_SOFT_RETRY BIT_ULL(40) +#define XHCI_EP_CTX_BROKEN_DCS BIT_ULL(41) unsigned int num_active_eps; unsigned int limit_active_eps;