[114/136] USB: xhci: Set -EREMOTEIO when xHC gives bad transfer length.

[Greg KH]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

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

commit 2f697f6cbff155b3ce4053a50cdf00b5be4dda11 upstream.

The xHCI hardware reports the number of bytes untransferred for a given
transfer buffer.  If the hardware reports a bytes untransferred value
greater than the submitted buffer size, we want to play it safe and say no
data was transferred.  If the driver considers a short packet to be an
error, remember to set -EREMOTEIO.

Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/host/xhci-ring.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1104,6 +1104,11 @@ static int handle_tx_event(struct xhci_h
 							"of %d bytes left\n",
 							TRB_LEN(event->transfer_len));
 					td->urb->actual_length = 0;
+					if (td->urb->transfer_flags &
+							URB_SHORT_NOT_OK)
+						status = -EREMOTEIO;
+					else
+						status = 0;
 				}
 				/* Don't overwrite a previously set error code */
 				if (status == -EINPROGRESS) {
@@ -1187,6 +1192,10 @@ td_cleanup:
 					urb->transfer_buffer_length,
 					urb->actual_length);
 			urb->actual_length = 0;
+			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+				status = -EREMOTEIO;
+			else
+				status = 0;
 		}
 		list_del(&td->td_list);
 		/* Was this TD slated to be cancelled but completed anyway? */


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