Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964929AbcCIXqI (ORCPT ); Wed, 9 Mar 2016 18:46:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:40714 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934599AbcCIXQT (ORCPT ); Wed, 9 Mar 2016 18:16:19 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mathias Nyman , Greg Kroah-Hartman , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 038/138] Revert "xhci: don't finish a TD if we get a short-transfer event mid TD" Date: Wed, 9 Mar 2016 15:12:45 -0800 Message-Id: <1457565265-15195-39-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457565265-15195-1-git-send-email-kamal@canonical.com> References: <1457565265-15195-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2339 Lines: 60 3.13.11-ckt36 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Mathias Nyman commit a6835090716a85f2297668ba593bd00e1051e662 upstream. This reverts commit e210c422b6fd ("xhci: don't finish a TD if we get a short transfer event mid TD") Turns out that most host controllers do not follow the xHCI specs and never send the second event for the last TRB in the TD if there was a short event mid-TD. Returning the URB directly after the first short-transfer event is far better than never returning the URB. (class drivers usually timeout after 30sec). For the hosts that do send the second event we will go back to treating it as misplaced event and print an error message for it. The origial patch was sent to stable kernels and needs to be reverted from there as well Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa --- 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 c207013..d4ce529 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2361,10 +2361,6 @@ 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 - @@ -2416,12 +2412,6 @@ 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); -- 2.7.0