From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753138AbbKOCHN (ORCPT ); Sat, 14 Nov 2015 21:07:13 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35247 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752238AbbKOCEv (ORCPT ); Sat, 14 Nov 2015 21:04:51 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Greg Kroah-Hartman" , "Mathias Nyman" Date: Sun, 15 Nov 2015 01:45:45 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 32/60] xhci: don't finish a TD if we get a short transfer event mid TD In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.247 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.73-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Nyman commit e210c422b6fdd2dc123bedc588f399aefd8bf9de upstream. If the difference is big enough between the bytes asked and received in a bulk transfer we can get a short transfer event pointing to a TRB in the middle of the TD. We don't want to handle the TD yet as we will anyway receive a new event for the last TRB in the TD. Hold off from finishing the TD and removing it from the list until we receive an event for the last TRB in the TD Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/host/xhci-ring.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2187,6 +2187,10 @@ static int process_bulk_intr_td(struct x 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 - @@ -2238,6 +2242,12 @@ static int process_bulk_intr_td(struct x 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);