media_entity_graph_walk_init() and media_entity_graph_walk_cleanup() are now mandatory. Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> --- Documentation/media-framework.txt | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/Documentation/media-framework.txt b/Documentation/media-framework.txt index b424de6..738a526 100644 --- a/Documentation/media-framework.txt +++ b/Documentation/media-framework.txt @@ -241,13 +241,22 @@ supported by the graph traversal API. To prevent infinite loops, the graph traversal code limits the maximum depth to MEDIA_ENTITY_ENUM_MAX_DEPTH, currently defined as 16. -Drivers initiate a graph traversal by calling +The graph traversal must be initialised calling + + media_entity_graph_walk_init(struct media_entity_graph *graph); + +The return value of the function must be checked. Should the number of +graph entities exceed the pre-allocated memory, it will also allocate +memory for the enumeration. + +Once initialised, the graph walk may be started by calling media_entity_graph_walk_start(struct media_entity_graph *graph, struct media_entity *entity); -The graph structure, provided by the caller, is initialized to start graph -traversal at the given entity. +The graph structure, provided by the caller, is initialized to start +graph traversal at the given entity. It is possible to start the graph +walk multiple times using the same graph struct. Drivers can then retrieve the next entity by calling @@ -255,8 +264,11 @@ Drivers can then retrieve the next entity by calling When the graph traversal is complete the function will return NULL. -Graph traversal can be interrupted at any moment. No cleanup function call is -required and the graph structure can be freed normally. +Graph traversal can be interrupted at any moment. Once the graph +structure is no longer needed, the resources that have been allocated +by media_entity_graph_walk_init() are released using + + media_entity_graph_walk_cleanup(struct media_entity_graph *graph); Helper functions can be used to find a link between two given pads, or a pad connected to another pad through an enabled link -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
