git.openwrt.org Git - openwrt/staging/981213.git/blob

   1 From 7bb9b7d36fa457a9fc463108d1228fd318891da4 Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.org>
   3 Date: Thu, 11 Jul 2019 17:55:43 +0100
   4 Subject: [PATCH] xhci: add quirk for host controllers that don't
   5  update endpoint DCS
   6
   7 Seen on a VLI VL805 PCIe to USB controller. For non-stream endpoints
   8 at least, if the xHC halts on a particular TRB due to an error then
   9 the DCS field in the Out Endpoint Context maintained by the hardware
  10 is not updated with the current cycle state.
  11
  12 Using the quirk XHCI_EP_CTX_BROKEN_DCS and instead fetch the DCS bit
  13 from the TRB that the xHC stopped on.
  14
  15 See: https://github.com/raspberrypi/linux/issues/3060
  16
  17 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
  18 ---
  19  drivers/usb/host/xhci-pci.c  |  4 +++-
  20  drivers/usb/host/xhci-ring.c | 26 +++++++++++++++++++++++++-
  21  drivers/usb/host/xhci.h      |  1 +
  22  3 files changed, 29 insertions(+), 2 deletions(-)
  23
  24 --- a/drivers/usb/host/xhci-pci.c
  25 +++ b/drivers/usb/host/xhci-pci.c
  26 @@ -258,8 +258,10 @@ static void xhci_pci_quirks(struct devic
  27                 xhci->quirks |= XHCI_BROKEN_STREAMS;
  28
  29         if (pdev->vendor == PCI_VENDOR_ID_VIA &&
  30 -                       pdev->device == 0x3483)
  31 +                       pdev->device == 0x3483) {
  32                 xhci->quirks |= XHCI_LPM_SUPPORT;
  33 +               xhci->quirks |= XHCI_EP_CTX_BROKEN_DCS;
  34 +       }
  35
  36         if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA &&
  37                 pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI)
  38 --- a/drivers/usb/host/xhci-ring.c
  39 +++ b/drivers/usb/host/xhci-ring.c
  40 @@ -550,7 +550,10 @@ void xhci_find_new_dequeue_state(struct
  41         struct xhci_virt_ep *ep = &dev->eps[ep_index];
  42         struct xhci_ring *ep_ring;
  43         struct xhci_segment *new_seg;
  44 +       struct xhci_segment *halted_seg = NULL;
  45         union xhci_trb *new_deq;
  46 +       union xhci_trb *halted_trb;
  47 +       int index = 0;
  48         dma_addr_t addr;
  49         u64 hw_dequeue;
  50         bool cycle_found = false;
  51 @@ -588,7 +591,28 @@ void xhci_find_new_dequeue_state(struct
  52         hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id);
  53         new_seg = ep_ring->deq_seg;
  54         new_deq = ep_ring->dequeue;
  55 -       state->new_cycle_state = hw_dequeue & 0x1;
  56 +
  57 +       /*
  58 +        * Quirk: xHC write-back of the DCS field in the hardware dequeue
  59 +        * pointer is wrong - use the cycle state of the TRB pointed to by
  60 +        * the dequeue pointer.
  61 +        */
  62 +       if (xhci->quirks & XHCI_EP_CTX_BROKEN_DCS &&
  63 +           !(ep->ep_state & EP_HAS_STREAMS))
  64 +               halted_seg = trb_in_td(xhci, cur_td->start_seg,
  65 +                                      cur_td->first_trb, cur_td->last_trb,
  66 +                                      hw_dequeue & ~0xf, false);
  67 +       if (halted_seg) {
  68 +               index = ((dma_addr_t)(hw_dequeue & ~0xf) - halted_seg->dma) /
  69 +                        sizeof(*halted_trb);
  70 +               halted_trb = &halted_seg->trbs[index];
  71 +               state->new_cycle_state = halted_trb->generic.field[3] & 0x1;
  72 +               xhci_dbg(xhci, "Endpoint DCS = %d TRB index = %d cycle = %d\n",
  73 +                        (u8)(hw_dequeue & 0x1), index,
  74 +                        state->new_cycle_state);
  75 +       } else {
  76 +               state->new_cycle_state = hw_dequeue & 0x1;
  77 +       }
  78         state->stream_id = stream_id;
  79
  80         /*
  81 --- a/drivers/usb/host/xhci.h
  82 +++ b/drivers/usb/host/xhci.h
  83 @@ -1874,6 +1874,7 @@ struct xhci_hcd {
  84  #define XHCI_DEFAULT_PM_RUNTIME_ALLOW  BIT_ULL(33)
  85  #define XHCI_RESET_PLL_ON_DISCONNECT   BIT_ULL(34)
  86  #define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
  87 +#define XHCI_EP_CTX_BROKEN_DCS BIT_ULL(36)
  88  #define XHCI_SKIP_PHY_INIT     BIT_ULL(37)
  89  #define XHCI_DISABLE_SPARSE    BIT_ULL(38)
  90  #define XHCI_NO_SOFT_RETRY     BIT_ULL(40)