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authorSakari Ailus <sakari.ailus@iki.fi>2015-12-16 11:32:22 -0200
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2016-01-11 12:19:18 -0200
commite03d220336dd69292370393f5eee98ac17eda308 (patch)
tree2815c164379aca3f8b937a5c44d3799b6b5d2f7d
parent5dd8775dc6b480f67be11108d7cd798fba724cab (diff)
download96b-common-e03d220336dd69292370393f5eee98ac17eda308.tar.gz
[media] media: Amend media graph walk API by init and cleanup functions
Add media_entity_graph_walk_init() and media_entity_graph_walk_cleanup() functions in order to dynamically allocate memory for the graph. This is not done in media_entity_graph_walk_start() as there are situations where e.g. correct error handling, that itself may not fail, requires successful graph walk. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
-rw-r--r--drivers/media/media-entity.c27
-rw-r--r--include/media/media-entity.h17
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