Patch "usb: xhci: Reset halted endpoint if trb is noop" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

usb: xhci: Reset halted endpoint if trb is noop

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-xhci-reset-halted-endpoint-if-trb-is-noop.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Lu Baolu <[email protected]>
Date: Fri, 6 Oct 2017 17:45:29 +0300
Subject: usb: xhci: Reset halted endpoint if trb is noop

From: Lu Baolu <[email protected]>

commit 810a624bd1b64b13ddcc2eb5c1880526a750a870 upstream.

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.

---
 drivers/usb/host/xhci-ring.c |   20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

@@ -2578,15 +2578,21 @@ static int handle_tx_event(struct xhci_h
 				(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;
 		}
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/usb-xhci-reset-halted-endpoint-if-trb-is-noop.patch