Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753609AbdHOBiR (ORCPT ); Mon, 14 Aug 2017 21:38:17 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57014 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753513AbdHOBTd (ORCPT ); Mon, 14 Aug 2017 21:19:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Bin Liu Subject: [PATCH 4.9 30/41] usb: core: unlink urbs from the tail of the endpoints urb_list Date: Mon, 14 Aug 2017 18:18:40 -0700 Message-Id: <20170815011810.206837134@linuxfoundation.org> X-Mailer: git-send-email 2.14.0 In-Reply-To: <20170815011808.667221255@linuxfoundation.org> References: <20170815011808.667221255@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1332 Lines: 41 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bin Liu commit 2eac13624364db5b5e1666ae0bb3a4d36bc56b6e upstream. While unlink an urb, if the urb has been programmed in the controller, the controller driver might do some hw related actions to tear down the urb. Currently usb_hcd_flush_endpoint() passes each urb from the head of the endpoint's urb_list to the controller driver, which could make the controller driver think each urb has been programmed and take the unnecessary actions for each urb. This patch changes the behavior in usb_hcd_flush_endpoint() to pass the urbs from the tail of the list, to avoid any unnecessary actions in an controller driver. Acked-by: Alan Stern Signed-off-by: Bin Liu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1877,7 +1877,7 @@ void usb_hcd_flush_endpoint(struct usb_d /* No more submits can occur */ spin_lock_irq(&hcd_urb_list_lock); rescan: - list_for_each_entry (urb, &ep->urb_list, urb_list) { + list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) { int is_in; if (urb->unlinked)