dma-buf/fence: add an lockdep_assert_held()

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: robclark

drivers/dma-buf/fence.c

@@ -68,6 +68,8 @@ int fence_signal_locked(struct fence *fence)
 	struct fence_cb *cur, *tmp;
 	int ret = 0;
 
+	lockdep_assert_held(fence->lock);
+
 	if (WARN_ON(!fence))
 		return -EINVAL;