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

   1 From 3eecda8f1b9f2cb03234208f06592bc88ededc37 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Mon, 7 Mar 2022 16:18:55 +0000
   4 Subject: [PATCH] xhci: add quirk for host controllers that don't update
   5  endpoint DCS
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   8 Content-Transfer-Encoding: 8bit
   9
  10 Seen on a VLI VL805 PCIe to USB controller. For non-stream endpoints
  11 at least, if the xHC halts on a particular TRB due to an error then
  12 the DCS field in the Out Endpoint Context maintained by the hardware
  13 is not updated with the current cycle state.
  14
  15 Using the quirk XHCI_EP_CTX_BROKEN_DCS and instead fetch the DCS bit
  16 from the TRB that the xHC stopped on.
  17
  18 [ bjorn: rebased to v5.14-rc2 ]
  19
  20 Link: https://github.com/raspberrypi/linux/issues/3060
  21 Cc: stable@vger.kernel.org
  22 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
  23 Signed-off-by: Bjørn Mork <bjorn@mork.no>
  24 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
  25 Link: https://lore.kernel.org/r/20211008092547.3996295-3-mathias.nyman@linux.intel.com
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27 ---
  28  drivers/usb/host/xhci-pci.c  |  1 +
  29  drivers/usb/host/xhci-ring.c | 23 ++++++++++++++++++++++-
  30  2 files changed, 23 insertions(+), 1 deletion(-)
  31
  32 --- a/drivers/usb/host/xhci-pci.c
  33 +++ b/drivers/usb/host/xhci-pci.c
  34 @@ -429,6 +429,7 @@ static void xhci_pci_quirks(struct devic
  35         if (pdev->vendor == PCI_VENDOR_ID_VIA && pdev->device == PCI_DEVICE_ID_VIA_VL805) {
  36                 xhci->quirks |= XHCI_LPM_SUPPORT;
  37                 xhci->quirks |= XHCI_TRB_OVERFETCH;
  38 +               xhci->quirks |= XHCI_EP_CTX_BROKEN_DCS;
  39         }
  40
  41         if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA &&
  42 --- a/drivers/usb/host/xhci-ring.c
  43 +++ b/drivers/usb/host/xhci-ring.c
  44 @@ -638,8 +638,11 @@ static int xhci_move_dequeue_past_td(str
  45         struct xhci_ring *ep_ring;
  46         struct xhci_command *cmd;
  47         struct xhci_segment *new_seg;
  48 +       struct xhci_segment *halted_seg = NULL;
  49         union xhci_trb *new_deq;
  50         int new_cycle;
  51 +       union xhci_trb *halted_trb;
  52 +       int index = 0;
  53         dma_addr_t addr;
  54         u64 hw_dequeue;
  55         bool cycle_found = false;
  56 @@ -658,7 +661,25 @@ static int xhci_move_dequeue_past_td(str
  57         hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id);
  58         new_seg = ep_ring->deq_seg;
  59         new_deq = ep_ring->dequeue;
  60 -       new_cycle = hw_dequeue & 0x1;
  61 +
  62 +       /*
  63 +        * Quirk: xHC write-back of the DCS field in the hardware dequeue
  64 +        * pointer is wrong - use the cycle state of the TRB pointed to by
  65 +        * the dequeue pointer.
  66 +        */
  67 +       if (xhci->quirks & XHCI_EP_CTX_BROKEN_DCS &&
  68 +           !(ep->ep_state & EP_HAS_STREAMS))
  69 +               halted_seg = trb_in_td(xhci, td, hw_dequeue & ~0xf, false);
  70 +       if (halted_seg) {
  71 +               index = ((dma_addr_t)(hw_dequeue & ~0xf) - halted_seg->dma) /
  72 +                        sizeof(*halted_trb);
  73 +               halted_trb = &halted_seg->trbs[index];
  74 +               new_cycle = halted_trb->generic.field[3] & 0x1;
  75 +               xhci_dbg(xhci, "Endpoint DCS = %d TRB index = %d cycle = %d\n",
  76 +                        (u8)(hw_dequeue & 0x1), index, new_cycle);
  77 +       } else {
  78 +               new_cycle = hw_dequeue & 0x1;
  79 +       }
  80
  81         /*
  82          * We want to find the pointer, segment and cycle state of the new trb