[PATCH v6 01/18] media: mc-entity: Record number of video devices in a pipeline

[Daniel Scally <dan.scally@ideasonboard.com>]

Record the number of video devices in a pipeline so that we can track
in a central location how many need to be started before drivers must
actually begin streaming.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
---
Changes in v6:

	- New patch. This is intended to support Sakari's requirement for the
	  driver not to start streaming before all of the video devices have
	  called streamon(). This was the cleanest way I could think to acheive
	  the goal, and lets us just check for start_count == required_count
	  before streaming.

 drivers/media/mc/mc-entity.c | 5 +++++
 include/media/media-entity.h | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 96dd0f6ccd0d..1e8186b13b55 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -596,6 +596,9 @@ static int media_pipeline_add_pad(struct media_pipeline *pipe,
 
 	list_add_tail(&ppad->list, &pipe->pads);
 
+	if (pad->entity->obj_type == MEDIA_ENTITY_TYPE_VIDEO_DEVICE)
+		pipe->required_count++;
+
 	dev_dbg(pad->graph_obj.mdev->dev,
 		"media pipeline: added pad '%s':%u\n",
 		pad->entity->name, pad->index);
@@ -713,6 +716,8 @@ static void media_pipeline_cleanup(struct media_pipeline *pipe)
 		list_del(&ppad->list);
 		kfree(ppad);
 	}
+
+	pipe->required_count = 0;
 }
 
 static int media_pipeline_populate(struct media_pipeline *pipe,
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 0393b23129eb..ab84458b40dc 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -104,12 +104,14 @@ struct media_graph {
  * @mdev:		The media device the pipeline is part of
  * @pads:		List of media_pipeline_pad
  * @start_count:	Media pipeline start - stop count
+ * @required_count:	Number of starts required to be "running"
  */
 struct media_pipeline {
 	bool allocated;
 	struct media_device *mdev;
 	struct list_head pads;
 	int start_count;
+	int required_count;
 };
 
 /**
-- 
2.34.1