diff --git a/drivers/char/drm/drm_stub.c b/drivers/char/drm/drm_stub.c
index 7b1d4e8..6f748e1 100644
--- a/drivers/char/drm/drm_stub.c
+++ b/drivers/char/drm/drm_stub.c
@@ -60,6 +60,7 @@
 	int retcode;
 
 	spin_lock_init(&dev->count_lock);
+	spin_lock_init(&dev->drw_lock);
 	init_timer(&dev->timer);
 	mutex_init(&dev->struct_mutex);
 	mutex_init(&dev->ctxlist_mutex);