USB: xhci: Handle stalled control endpoints.

When a control endpoint stalls, the next control transfer will clear the
stall.  The USB core doesn't call down to the host controller driver's
endpoint_reset() method when control endpoints stall, so the xHCI driver
has to do all its stall handling for internal state in its interrupt handler.

When the host stalls on a control endpoint, it may stop on the data phase
or status phase of the control transfer.  Like other stalled endpoints,
the xHCI driver needs to queue a Reset Endpoint command and move the
hardware's control endpoint ring dequeue pointer past the failed control
transfer (with a Set TR Dequeue Pointer or a Configure Endpoint command).

Since the USB core doesn't call usb_hcd_reset_endpoint() for control
endpoints, we need to do this in interrupt context when we get notified of
the stalled transfer.  URBs may be queued to the hardware before these two
commands complete.  The endpoint queue will be restarted once both
commands complete.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 4e18f4edf5aa..4353c1c78935 100644
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -1230,6 +1230,25 @@ void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 	xhci_zero_in_ctx(xhci, virt_dev);
 }
 
+void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
+		struct usb_device *udev, struct usb_host_endpoint *ep,
+		unsigned int ep_index, struct xhci_ring *ep_ring)
+{
+	struct xhci_dequeue_state deq_state;
+
+	xhci_dbg(xhci, "Cleaning up stalled endpoint ring\n");
+	/* We need to move the HW's dequeue pointer past this TD,
+	 * or it will attempt to resend it on the next doorbell ring.
+	 */
+	xhci_find_new_dequeue_state(xhci, udev->slot_id,
+			ep_index, ep_ring->stopped_td, &deq_state);
+
+	xhci_dbg(xhci, "Queueing new dequeue state\n");
+	xhci_queue_new_dequeue_state(xhci, ep_ring,
+			udev->slot_id,
+			ep_index, &deq_state);
+}
+
 /* Deal with stalled endpoints.  The core should have sent the control message
  * to clear the halt condition.  However, we need to make the xHCI hardware
  * reset its sequence number, since a device will expect a sequence number of
@@ -1244,7 +1263,6 @@ void xhci_endpoint_reset(struct usb_hcd *hcd,
 	unsigned int ep_index;
 	unsigned long flags;
 	int ret;
-	struct xhci_dequeue_state deq_state;
 	struct xhci_ring *ep_ring;
 
 	xhci = hcd_to_xhci(hcd);
@@ -1261,6 +1279,10 @@ void xhci_endpoint_reset(struct usb_hcd *hcd,
 				ep->desc.bEndpointAddress);
 		return;
 	}
+	if (usb_endpoint_xfer_control(&ep->desc)) {
+		xhci_dbg(xhci, "Control endpoint stall already handled.\n");
+		return;
+	}
 
 	xhci_dbg(xhci, "Queueing reset endpoint command\n");
 	spin_lock_irqsave(&xhci->lock, flags);
@@ -1271,16 +1293,7 @@ void xhci_endpoint_reset(struct usb_hcd *hcd,
 	 * command.  Better hope that last command worked!
 	 */
 	if (!ret) {
-		xhci_dbg(xhci, "Cleaning up stalled endpoint ring\n");
-		/* We need to move the HW's dequeue pointer past this TD,
-		 * or it will attempt to resend it on the next doorbell ring.
-		 */
-		xhci_find_new_dequeue_state(xhci, udev->slot_id,
-				ep_index, ep_ring->stopped_td, &deq_state);
-		xhci_dbg(xhci, "Queueing new dequeue state\n");
-		xhci_queue_new_dequeue_state(xhci, ep_ring,
-				udev->slot_id,
-				ep_index, &deq_state);
+		xhci_cleanup_stalled_ring(xhci, udev, ep, ep_index, ep_ring);
 		kfree(ep_ring->stopped_td);
 		xhci_ring_cmd_db(xhci);
 	}