xhci: Don't warn on empty ring for suspended devices.

When a device attached to the roothub is suspended, the endpoint rings
are stopped.  The host may generate a completion event with the
completion code set to 'Stopped' or 'Stopped Invalid' when the ring is
halted.  The current xHCI code prints a warning in that case, which can
be really annoying if the USB device is coming into and out of suspend.

Remove the unnecessary warning.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Stephen Hemminger <stephen@networkplumber.org>

1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9652dae95942..1969c001b3f9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2463,14 +2463,21 @@ static int handle_tx_event(struct xhci_hcd *xhci,
                  * TD list.
                  */
                 if (list_empty(&ep_ring->td_list)) {
-                        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);
-                        xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
-                                 (le32_to_cpu(event->flags) &
-                                  TRB_TYPE_BITMASK)>>10);
-                        xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
+                        /*
+                         * A stopped endpoint may generate an extra completion
+                         * event if the device was suspended.  Don't print
+                         * warnings.
+                         */
+                        if (!(trb_comp_code == COMP_STOP ||
+                                                trb_comp_code == COMP_STOP_INVAL)) {
+                                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);
+                                xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
+                                                (le32_to_cpu(event->flags) &
+                                                 TRB_TYPE_BITMASK)>>10);
+                                xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
+                        }
                         if (ep->skip) {
                                 ep->skip = false;
                                 xhci_dbg(xhci, "td_list is empty while skip "