From af88be3887c1a0b20d0792c3c237a67c73ef3286 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 11 Jan 2012 06:25:15 -0300 Subject: [media] media: Add link_validate() op to check links to the sink pad The purpose of the link_validate() op is to allow an entity driver to ensure that the properties of the pads at the both ends of the link are suitable for starting the pipeline. link_validate is called on sink pads on active links which belong to the active part of the graph. Signed-off-by: Sakari Ailus Acked-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-entity.c | 57 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index 056138f63c7d..e1cd13283407 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -214,23 +214,76 @@ EXPORT_SYMBOL_GPL(media_entity_graph_walk_next); * pipeline pointer must be identical for all nested calls to * media_entity_pipeline_start(). */ -void media_entity_pipeline_start(struct media_entity *entity, - struct media_pipeline *pipe) +__must_check int media_entity_pipeline_start(struct media_entity *entity, + struct media_pipeline *pipe) { struct media_device *mdev = entity->parent; struct media_entity_graph graph; + struct media_entity *entity_err = entity; + int ret; mutex_lock(&mdev->graph_mutex); media_entity_graph_walk_start(&graph, entity); while ((entity = media_entity_graph_walk_next(&graph))) { + unsigned int i; + entity->stream_count++; WARN_ON(entity->pipe && entity->pipe != pipe); entity->pipe = pipe; + + /* Already streaming --- no need to check. */ + if (entity->stream_count > 1) + continue; + + if (!entity->ops || !entity->ops->link_validate) + continue; + + 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) + continue; + + ret = entity->ops->link_validate(link); + if (ret < 0 && ret != -ENOIOCTLCMD) + goto error; + } } mutex_unlock(&mdev->graph_mutex); + + return 0; + +error: + /* + * Link validation on graph failed. We revert what we did and + * return the error. + */ + media_entity_graph_walk_start(&graph, entity_err); + + while ((entity_err = media_entity_graph_walk_next(&graph))) { + entity_err->stream_count--; + if (entity_err->stream_count == 0) + entity_err->pipe = NULL; + + /* + * We haven't increased stream_count further than this + * so we quit here. + */ + if (entity_err == entity) + break; + } + + mutex_unlock(&mdev->graph_mutex); + + return ret; } EXPORT_SYMBOL_GPL(media_entity_pipeline_start); -- cgit v1.2.3