2 files changed, 32 insertions, 2 deletions

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index ec42872d11cf..dec55d53d24a 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2444,14 +2444,16 @@ int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd)
 EXPORT_SYMBOL(v4l2_ctrl_subdev_log_status);
 
 /* Call s_ctrl for all controls owned by the handler */
-int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
+int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
 {
 	struct v4l2_ctrl *ctrl;
 	int ret = 0;
 
 	if (hdl == NULL)
 		return 0;
-	mutex_lock(hdl->lock);
+
+	lockdep_assert_held(hdl->lock);
+
 	list_for_each_entry(ctrl, &hdl->ctrls, node)
 		ctrl->done = false;
 
@@ -2476,7 +2478,22 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
 		if (ret)
 			break;
 	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__v4l2_ctrl_handler_setup);
+
+int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
+{
+	int ret;
+
+	if (hdl == NULL)
+		return 0;
+
+	mutex_lock(hdl->lock);
+	ret = __v4l2_ctrl_handler_setup(hdl);
 	mutex_unlock(hdl->lock);
+
 	return ret;
 }
 EXPORT_SYMBOL(v4l2_ctrl_handler_setup);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index bee1404391dd..2d2aed56922f 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -458,6 +458,19 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
 }
 
 /**
+ * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
+ * to the handler to initialize the hardware to the current control values. The
+ * caller is responsible for acquiring the control handler mutex on behalf of
+ * __v4l2_ctrl_handler_setup().
+ * @hdl:	The control handler.
+ *
+ * Button controls will be skipped, as are read-only controls.
+ *
+ * If @hdl == NULL, then this just returns 0.
+ */
+int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
+
+/**
  * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
  * to the handler to initialize the hardware to the current control values.
  * @hdl:	The control handler.