Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935263Ab2JXTn0 (ORCPT ); Wed, 24 Oct 2012 15:43:26 -0400 Received: from mail.pxnet.com ([89.1.7.7]:46484 "EHLO mail.pxnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934141Ab2JXTnX (ORCPT ); Wed, 24 Oct 2012 15:43:23 -0400 X-Greylist: delayed 2178 seconds by postgrey-1.27 at vger.kernel.org; Wed, 24 Oct 2012 15:43:22 EDT From: Tilman Schmidt Date: Wed, 24 Oct 2012 20:44:32 +0200 Subject: [PATCH] bas_gigaset: fix pre_reset handling To: Karsten Keil , David Miller Cc: Oliver Neukum , Hansjoerg Lipp , gigaset307x-common@lists.sourceforge.net, linux-usb@vger.kernel.org, i4ldeveloper@listserv.isdn4linux.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20121024-patch-gigaset-01.tilman@imap.cc> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2544 Lines: 66 The delayed work function int_in_work() may call usb_reset_device() and thus, indirectly, the driver's pre_reset method. Trying to cancel the work synchronously in that situation would deadlock. Fix by avoiding cancel_work_sync() in the pre_reset method. If the reset was NOT initiated by int_in_work() this might cause int_in_work() to run after the post_reset method, with urb_int_in already resubmitted, so handle that case gracefully. Signed-off-by: Tilman Schmidt --- drivers/isdn/gigaset/bas-gigaset.c | 19 ++++++++++++++++--- 1 files changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c index 5275887..c44950d 100644 --- a/drivers/isdn/gigaset/bas-gigaset.c +++ b/drivers/isdn/gigaset/bas-gigaset.c @@ -617,7 +617,13 @@ static void int_in_work(struct work_struct *work) if (rc == 0) /* success, resubmit interrupt read URB */ rc = usb_submit_urb(urb, GFP_ATOMIC); - if (rc != 0 && rc != -ENODEV) { + + switch (rc) { + case 0: /* success */ + case -ENODEV: /* device gone */ + case -EINVAL: /* URB already resubmitted, or terminal badness */ + break; + default: /* failure: try to recover by resetting the device */ dev_err(cs->dev, "clear halt failed: %s\n", get_usb_rcmsg(rc)); rc = usb_lock_device_for_reset(ucs->udev, ucs->interface); if (rc == 0) { @@ -2442,7 +2448,9 @@ static void gigaset_disconnect(struct usb_interface *interface) } /* gigaset_suspend - * This function is called before the USB connection is suspended. + * This function is called before the USB connection is suspended + * or before the USB device is reset. + * In the latter case, message == PMSG_ON. */ static int gigaset_suspend(struct usb_interface *intf, pm_message_t message) { @@ -2498,7 +2506,12 @@ static int gigaset_suspend(struct usb_interface *intf, pm_message_t message) del_timer_sync(&ucs->timer_atrdy); del_timer_sync(&ucs->timer_cmd_in); del_timer_sync(&ucs->timer_int_in); - cancel_work_sync(&ucs->int_in_wq); + + /* don't try to cancel int_in_wq from within reset as it + * might be the one requesting the reset + */ + if (message.event != PM_EVENT_ON) + cancel_work_sync(&ucs->int_in_wq); gig_dbg(DEBUG_SUSPEND, "suspend complete"); return 0; -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/