From de49c285a3604955dcbf746edd871f2a4f128122 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Sun, 13 Oct 2013 08:00:26 -0300 Subject: [PATCH] [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 Tested-by: Sylwester Nawrocki Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-entity.c | 41 ++++++++++++++++++++++++++++++++++------- 1 file changed, 34 insertions(+), 7 deletions(-) diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index 2c286c3..37c334e 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -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]; - - /* Is this pad part of an enabled link? */ - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) - continue; - - /* Are we the sink or not? */ - if (link->sink->entity != entity) + struct media_pad *pad = link->sink->entity == entity + ? link->sink : link->source; + + /* 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); + + /* + * 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); -- 2.7.4