From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Tilman Schmidt , "David S. Miller" Subject: [ 26/37] bas_gigaset: fix pre_reset handling Date: Fri, 30 Nov 2012 10:46:13 -0800 Message-Id: <20121130183900.068126321@linuxfoundation.org> In-Reply-To: <20121130183857.166228045@linuxfoundation.org> References: <20121130183857.166228045@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tilman Schmidt commit c6fdd8e5d0c65bb8821dc6da26ee1a2ddd58b3cc upstream. 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/isdn/gigaset/bas-gigaset.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) --- a/drivers/isdn/gigaset/bas-gigaset.c +++ b/drivers/isdn/gigaset/bas-gigaset.c @@ -616,7 +616,13 @@ static void int_in_work(struct work_stru 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) { @@ -2437,7 +2443,9 @@ static void gigaset_disconnect(struct us } /* 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) { @@ -2493,7 +2501,12 @@ static int gigaset_suspend(struct usb_in 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;