Commit de49c285 authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab
Browse files

[media] media: Check for active links on pads with MEDIA_PAD_FL_MUST_CONNECT flag 



Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is not
connected by an active link.
This patch makes it possible to avoid drivers having to check for the most
common case of link state validation: a sink pad that must be connected.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@iki.fi>
Tested-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent d0700c51

drivers/media/media-entity.c

+34 −7
Original line number Diff line number Diff line
@@ -235,6 +235,8 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity, 
	media_entity_graph_walk_start(&graph, entity);



	while ((entity = media_entity_graph_walk_next(&graph))) {

		DECLARE_BITMAP(active, entity->num_pads);

		DECLARE_BITMAP(has_no_links, entity->num_pads);

		unsigned int i;



		entity->stream_count++;
@@ -248,21 +250,46 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity, 
		if (!entity->ops || !entity->ops->link_validate)

			continue;



		bitmap_zero(active, entity->num_pads);

		bitmap_fill(has_no_links, entity->num_pads);



		for (i = 0; i < entity->num_links; i++) {

			struct media_link *link = &entity->links[i];

			struct media_pad *pad = link->sink->entity == entity

						? link->sink : link->source;



			/* Is this pad part of an enabled link? */

			if (!(link->flags & MEDIA_LNK_FL_ENABLED))

				continue;

			/* Mark that a pad is connected by a link. */

			bitmap_clear(has_no_links, pad->index, 1);



			/*

			 * Pads that either do not need to connect or

			 * are connected through an enabled link are

			 * fine.

			 */

			if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) ||

			    link->flags & MEDIA_LNK_FL_ENABLED)

				bitmap_set(active, pad->index, 1);



			/* Are we the sink or not? */

			if (link->sink->entity != entity)

			/*

			 * Link validation will only take place for

			 * sink ends of the link that are enabled.

			 */

			if (link->sink != pad ||

			    !(link->flags & MEDIA_LNK_FL_ENABLED))

				continue;



			ret = entity->ops->link_validate(link);

			if (ret < 0 && ret != -ENOIOCTLCMD)

				goto error;

		}



		/* Either no links or validated links are fine. */

		bitmap_or(active, active, has_no_links, entity->num_pads);



		if (!bitmap_full(active, entity->num_pads)) {

			ret = -EPIPE;

			goto error;

		}

	}



	mutex_unlock(&mdev->graph_mutex);