Make it explicit that the function is always called with ctrl_mutex
being held.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 3f8ae35cb3bc..99ddc5e9dff8 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1946,6 +1946,8 @@ int uvc_ctrl_set(struct uvc_fh *handle,
 	s32 max;
 	int ret;
 
+	lockdep_assert_held(&chain->ctrl_mutex);
+
 	if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
 		return -EACCES;
 
-- 
2.47.0.338.g60cca15819-goog