[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: Sakari Ailus <sakari.ailus@iki.fi>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Sakari Ailus 2013-10-13 08:00:26 -03:00 committed by Mauro Carvalho Chehab
parent d0700c5175
commit de49c285a3

View File

@ -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);
/* Are we the sink or not? */
if (link->sink->entity != entity)
/*
* 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);
/*
* 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);