diff options
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 974d49205569..38fb6820489d 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -417,6 +417,20 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci, state->new_cycle_state = ~(state->new_cycle_state) & 0x1; next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr); + /* + * If there is only one segment in a ring, find_trb_seg()'s while loop + * will not run, and it will return before it has a chance to see if it + * needs to toggle the cycle bit. It can't tell if the stalled transfer + * ended just before the link TRB on a one-segment ring, or if the TD + * wrapped around the top of the ring, because it doesn't have the TD in + * question. Look for the one-segment case where stalled TRB's address + * is greater than the new dequeue pointer address. + */ + if (ep_ring->first_seg == ep_ring->first_seg->next && + state->new_deq_ptr < dev->eps[ep_index].stopped_trb) + state->new_cycle_state ^= 0x1; + xhci_dbg(xhci, "Cycle state = 0x%x\n", state->new_cycle_state); + /* Don't update the ring cycle state for the producer (us). */ xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n", state->new_deq_seg); |