diff options
| -rw-r--r-- | drivers/media/media-entity.c | 27 | ||||
| -rw-r--r-- | include/media/media-entity.h | 17 |
2 files changed, 39 insertions, 5 deletions
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index 83cfde6dcb1c..9bf96c71374e 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -282,6 +282,33 @@ static struct media_entity *stack_pop(struct media_entity_graph *graph) #define link_top(en) ((en)->stack[(en)->top].link) #define stack_top(en) ((en)->stack[(en)->top].entity) +/** + * media_entity_graph_walk_init - Allocate resources for graph walk + * @graph: Media graph structure that will be used to walk the graph + * @mdev: Media device + * + * Reserve resources for graph walk in media device's current + * state. The memory must be released using + * media_entity_graph_walk_free(). + * + * Returns error on failure, zero on success. + */ +__must_check int media_entity_graph_walk_init( + struct media_entity_graph *graph, struct media_device *mdev) +{ + return 0; +} +EXPORT_SYMBOL_GPL(media_entity_graph_walk_init); + +/** + * media_entity_graph_walk_cleanup - Release resources related to graph walking + * @graph: Media graph structure that was used to walk the graph + */ +void media_entity_graph_walk_cleanup(struct media_entity_graph *graph) +{ +} +EXPORT_SYMBOL_GPL(media_entity_graph_walk_cleanup); + void media_entity_graph_walk_start(struct media_entity_graph *graph, struct media_entity *entity) { diff --git a/include/media/media-entity.h b/include/media/media-entity.h index 4dc3bef72c9d..7f028ea84911 100644 --- a/include/media/media-entity.h +++ b/include/media/media-entity.h @@ -699,6 +699,10 @@ struct media_pad *media_entity_remote_pad(struct media_pad *pad); */ struct media_entity *media_entity_get(struct media_entity *entity); +__must_check int media_entity_graph_walk_init( + struct media_entity_graph *graph, struct media_device *mdev); +void media_entity_graph_walk_cleanup(struct media_entity_graph *graph); + /** * media_entity_put - Release the reference to the parent module * @@ -715,13 +719,16 @@ void media_entity_put(struct media_entity *entity); * @graph: Media graph structure that will be used to walk the graph * @entity: Starting entity * - * This function initializes the graph traversal structure to walk the entities - * graph starting at the given entity. The traversal structure must not be - * modified by the caller during graph traversal. When done the structure can - * safely be freed. + * Before using this function, media_entity_graph_walk_init() must be + * used to allocate resources used for walking the graph. This + * function initializes the graph traversal structure to walk the + * entities graph starting at the given entity. The traversal + * structure must not be modified by the caller during graph + * traversal. After the graph walk, the resources must be released + * using media_entity_graph_walk_cleanup(). */ void media_entity_graph_walk_start(struct media_entity_graph *graph, - struct media_entity *entity); + struct media_entity *entity); /** * media_entity_graph_walk_next - Get the next entity in the graph |