[46/65] USB: cdc-wdm: call wake_up_all to allow driver to shutdown on device removal

From: Greg KH
Date: Wed Feb 01 2012 - 16:39:59 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bjørn Mork <bjorn@xxxxxxx>

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@xxxxxxx>
Cc: Oliver Neukum <oliver@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/class/cdc-wdm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -786,13 +786,13 @@ static void wdm_disconnect(struct usb_in
/* 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);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/