media: omap3isp: Acquire graph mutex for graph traversal

Acquire the graph_mutex for traversing the media graph. This seems to have
been missing all the time.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/omap3isp/isp.c

@@ -691,6 +691,8 @@ static int isp_pipeline_enable(struct isp_pipeline *pipe,
 
 	pipe->do_propagation = false;
 
+	mutex_lock(&isp->media_dev.graph_mutex);
+
 	entity = &pipe->output->video.entity;
 	while (1) {
 		pad = &entity->pads[0];
@@ -705,8 +707,10 @@ static int isp_pipeline_enable(struct isp_pipeline *pipe,
 		subdev = media_entity_to_v4l2_subdev(entity);
 
 		ret = v4l2_subdev_call(subdev, video, s_stream, mode);
-		if (ret < 0 && ret != -ENOIOCTLCMD)
+		if (ret < 0 && ret != -ENOIOCTLCMD) {
+			mutex_unlock(&isp->media_dev.graph_mutex);
 			return ret;
+		}
 
 		if (subdev == &isp->isp_ccdc.subdev) {
 			v4l2_subdev_call(&isp->isp_aewb.subdev, video,
@@ -723,6 +727,8 @@ static int isp_pipeline_enable(struct isp_pipeline *pipe,
 			break;
 	}
 
+	mutex_unlock(&isp->media_dev.graph_mutex);
+
 	return 0;
 }
 
@@ -2028,6 +2034,8 @@ static int isp_subdev_notifier_complete(struct v4l2_async_notifier *async)
 	struct v4l2_subdev *sd;
 	int ret;
 
+	mutex_lock(&isp->media_dev.graph_mutex);
+
 	ret = media_entity_enum_init(&isp->crashed, &isp->media_dev);
 	if (ret)
 		return ret;
@@ -2038,10 +2046,14 @@ static int isp_subdev_notifier_complete(struct v4l2_async_notifier *async)
 
 		ret = isp_link_entity(isp, &sd->entity,
 				      v4l2_subdev_to_bus_cfg(sd)->interface);
-		if (ret < 0)
+		if (ret < 0) {
+			mutex_unlock(&isp->media_dev.graph_mutex);
 			return ret;
+		}
 	}
 
+	mutex_unlock(&isp->media_dev.graph_mutex);
+
 	ret = v4l2_device_register_subdev_nodes(&isp->v4l2_dev);
 	if (ret < 0)
 		return ret;