From 705bc230789927f96d6c9c70dc5475ebaf08aa54 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, 29 insertions(+), 2 deletions(-) --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -226,8 +226,10 @@ static void xhci_pci_quirks(struct devic xhci->quirks |= XHCI_BROKEN_STREAMS; if (pdev->vendor == PCI_VENDOR_ID_VIA && - pdev->device == 0x3483) + pdev->device == 0x3483) { xhci->quirks |= XHCI_LPM_SUPPORT; + xhci->quirks |= XHCI_EP_CTX_BROKEN_DCS; + } if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA && pdev->device == 0x1042) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -520,7 +520,10 @@ void xhci_find_new_dequeue_state(struct struct xhci_virt_ep *ep = &dev->eps[ep_index]; struct xhci_ring *ep_ring; struct xhci_segment *new_seg; + struct xhci_segment *halted_seg = NULL; union xhci_trb *new_deq; + union xhci_trb *halted_trb; + int index = 0; dma_addr_t addr; u64 hw_dequeue; bool cycle_found = false; @@ -541,7 +544,28 @@ void xhci_find_new_dequeue_state(struct hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id); new_seg = ep_ring->deq_seg; new_deq = ep_ring->dequeue; - state->new_cycle_state = 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; /* --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1872,6 +1872,7 @@ struct xhci_hcd { #define XHCI_ZERO_64B_REGS BIT_ULL(32) #define XHCI_RESET_PLL_ON_DISCONNECT BIT_ULL(34) #define XHCI_SNPS_BROKEN_SUSPEND BIT_ULL(35) +#define XHCI_EP_CTX_BROKEN_DCS BIT_ULL(36) unsigned int num_active_eps; unsigned int limit_active_eps;