From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933187AbcHJUtH (ORCPT ); Wed, 10 Aug 2016 16:49:07 -0400 Received: from mga04.intel.com ([192.55.52.120]:57051 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752885AbcHJSMD (ORCPT ); Wed, 10 Aug 2016 14:12:03 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,498,1464678000"; d="scan'208";a="1011674520" From: Lu Baolu To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu , stable@vger.kernel.org, Alan Stern Subject: [PATCH v2 1/1] usb: misc: usbtest: add fix for driver hang Date: Wed, 10 Aug 2016 13:42:29 +0800 Message-Id: <1470807764-6336-1-git-send-email-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In sg_timeout(), req->status is set to "-ETIMEDOUT" before calling into usb_sg_cancel(). usb_sg_cancel() will do nothing and return directly if req->status has been set to a non-zero value. This will cause driver hang whenever transfer time out is triggered. This patch fixes this issue. It could be backported to stable kernel with version later than v3.15. Cc: stable@vger.kernel.org # 3.15+ Cc: Alan Stern Signed-off-by: Lu Baolu --- v1->v2: - Set retval to -ETIMEDOUT after timed out - Removed the kernel log in patch description drivers/usb/misc/usbtest.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c index 6b978f0..c273e11 100644 --- a/drivers/usb/misc/usbtest.c +++ b/drivers/usb/misc/usbtest.c @@ -585,7 +585,6 @@ static void sg_timeout(unsigned long _req) { struct usb_sg_request *req = (struct usb_sg_request *) _req; - req->status = -ETIMEDOUT; usb_sg_cancel(req); } @@ -616,8 +615,10 @@ static int perform_sglist( mod_timer(&sg_timer, jiffies + msecs_to_jiffies(SIMPLE_IO_TIMEOUT)); usb_sg_wait(req); - del_timer_sync(&sg_timer); - retval = req->status; + if (unlikely(!del_timer_sync(&sg_timer))) + retval = -ETIMEDOUT; + else + retval = req->status; /* FIXME check resulting data pattern */ -- 2.1.4