From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> When a URB is cancled, xhci driver turns the untransferred trbs into no-ops. If an endpoint stalls on a no-op trb that belongs to the cancelled URB, the event handler won't reset the endpoint. Hence, it will stay halted. Link: http://marc.info/?l=linux-usb&m=149582598330127&w=2 Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> --- drivers/usb/host/xhci-ring.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 48ae15af..82c746e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2580,15 +2580,21 @@ static int handle_tx_event(struct xhci_hcd *xhci, (struct xhci_generic_trb *) ep_trb); /* - * No-op TRB should not trigger interrupts. - * If ep_trb is a no-op TRB, it means the - * corresponding TD has been cancelled. Just ignore - * the TD. + * No-op TRB could trigger interrupts in a case where + * a URB was killed and a STALL_ERROR happens right + * after the endpoint ring stopped. Reset the halted + * endpoint. Otherwise, the endpoint remains stalled + * indefinitely. */ if (trb_is_noop(ep_trb)) { - xhci_dbg(xhci, - "ep_trb is a no-op TRB. Skip it for slot %u ep %u\n", - slot_id, ep_index); + if (trb_comp_code == COMP_STALL_ERROR || + xhci_requires_manual_halt_cleanup(xhci, ep_ctx, + trb_comp_code)) + xhci_cleanup_halted_endpoint(xhci, slot_id, + ep_index, + ep_ring->stream_id, + td, ep_trb, + EP_HARD_RESET); goto cleanup; } -- 2.7.4