usb: xhci: Allow context state errors when halting an endpoint

There is a race where an endpoint may halt by itself while we are trying
to halt it, which results in a context state error. See xHCI 4.6.9 which
mentions this case.

This also avoids BUGging when we attempt to stop an endpoint which was
already stopped to begin with, which is probably a bug elsewhere but
not a good reason to crash.

Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Marek Vasut <marex@denx.de>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d21e76e0bdb63cf2494cb7274457ed8744685ae7..e02a6e300c4fa8647f23e615d6b7d0c9b022750f 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -545,6 +545,7 @@ static void abort_td(struct usb_device *udev, int ep_index)
        struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
        struct xhci_ring *ring =  ctrl->devs[udev->slot_id]->eps[ep_index].ring;
        union xhci_trb *event;
+       xhci_comp_code comp;
        trb_type type;
        u64 addr;
        u32 field;
@@ -573,10 +574,11 @@ static void abort_td(struct usb_device *udev, int ep_index)
                printf("abort_td: Expected a TRB_TRANSFER TRB first\n");
        }
 
+       comp = GET_COMP_CODE(le32_to_cpu(event->event_cmd.status));
        BUG_ON(type != TRB_COMPLETION ||
                TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
-               != udev->slot_id || GET_COMP_CODE(le32_to_cpu(
-               event->event_cmd.status)) != COMP_SUCCESS);
+               != udev->slot_id || (comp != COMP_SUCCESS && comp
+               != COMP_CTX_STATE));
        xhci_acknowledge_event(ctrl);
 
        addr = xhci_trb_virt_to_dma(ring->enq_seg,