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 bdfa96d..ed43173 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -786,13 +786,13 @@
/* 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);