[ 07/26] xhci: Dont warn on empty ring for suspended devices.

From: Greg Kroah-Hartman
Date: Thu May 09 2013 - 18:43:37 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>

commit a83d6755814e4614ba77e15d82796af0f695c6b8 upstream.

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@xxxxxxxxxxxxxxx>
Tested-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Cc: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/host/xhci-ring.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2459,14 +2459,21 @@ static int handle_tx_event(struct xhci_h
* 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 "


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