[SRU][Precise] Revert "xhci: don't finish a TD if we get a short transfer event mid TD"

[Luis Henriques]

BugLink: https://bugs.launchpad.net/bugs/1529077

This reverts commit cd775cea7767dc609c449072eb4c16fd1ce0048c, which was
commit e210c422b6fdd2dc123bedc588f399aefd8bf9de upstream.

This commit is causing a regression in mainline kernel and in several
stable kernels that included it.  Here's some links for more bug reports:

https://bugs.debian.org/808602
https://bugs.debian.org/808953

Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/host/xhci-ring.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9f57111a3e43..5fdb85fba447 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2187,10 +2187,6 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));
 	/* Fast path - was this the last TRB in the TD for this URB? */
 	if (event_trb == td->last_trb) {
-		if (td->urb_length_set && trb_comp_code == COMP_SHORT_TX)
-			return finish_td(xhci, td, event_trb, event, ep,
-					 status, false);
-
 		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
 			td->urb->actual_length =
 				td->urb->transfer_buffer_length -
@@ -2242,12 +2238,6 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
 			td->urb->actual_length +=
 				TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
-
-		if (trb_comp_code == COMP_SHORT_TX) {
-			xhci_dbg(xhci, "mid bulk/intr SP, wait for last TRB event\n");
-			td->urb_length_set = true;
-			return 0;
-		}
 	}
 
 	return finish_td(xhci, td, event_trb, event, ep, status, false);