xHC can generate two events for a short transfer if the short TRB and last TRB in the TD are not the same TRB.
The driver will handle the TD after the first short event, and remove it from its internal list. Driver then incorrectly prints a warning for the second event:
"WARN Event TRB for slot x ep y with no TDs queued"
Fix this by not printing a warning if we get a event on a empty list if the previous event was a short event.
Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci-ring.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index c239c68..6eb87c6 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2477,12 +2477,16 @@ static int handle_tx_event(struct xhci_hcd *xhci, */ if (list_empty(&ep_ring->td_list)) { /* - * A stopped endpoint may generate an extra completion - * event if the device was suspended. Don't print - * warnings. + * Don't print wanings if it's due to a stopped endpoint + * generating an extra completion event if the device + * was suspended. Or, a event for the last TRB of a + * short TD we already got a short event for. + * The short TD is already removed from the TD list. */ + if (!(trb_comp_code == COMP_STOPPED || - trb_comp_code == COMP_STOPPED_LENGTH_INVALID)) { + trb_comp_code == COMP_STOPPED_LENGTH_INVALID || + ep_ring->last_td_was_short)) { xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n", TRB_TO_SLOT_ID(le32_to_cpu(event->flags)), ep_index);