From: Bjørn Mork <bjorn@mork.no>
Date: Mon, 16 Jan 2012 14:11:57 +0000 (+0100)
Subject: USB: cdc-wdm: call wake_up_all to allow driver to shutdown on device removal
X-Git-Tag: v3.2.3~24
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4ac2b6d3cc5d685f8701a392bdea04a401333a11;p=karo-tx-linux.git

USB: cdc-wdm: call wake_up_all to allow driver to shutdown on device removal

commit 62aaf24dc125d7c55c93e313d15611f152b030c7 upstream.

wdm_disconnect() waits for the mutex held by wdm_read() before
calling wake_up_all().  This causes a deadlock, preventing device removal
to complete.  Do the wake_up_all() before we start waiting for the locks.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 4a29a8068946..d2cda2607bd5 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -786,13 +786,13 @@ static void wdm_disconnect(struct usb_interface *intf)
 	/* to terminate pending flushes */
 	clear_bit(WDM_IN_USE, &desc->flags);
 	spin_unlock_irqrestore(&desc->iuspin, flags);
+	wake_up_all(&desc->wait);
 	mutex_lock(&desc->rlock);
 	mutex_lock(&desc->wlock);
 	kill_urbs(desc);
 	cancel_work_sync(&desc->rxwork);
 	mutex_unlock(&desc->wlock);
 	mutex_unlock(&desc->rlock);
-	wake_up_all(&desc->wait);
 	if (!desc->count)
 		cleanup(desc);
 	mutex_unlock(&wdm_mutex);