Re: [PATCH 05/19] media: Move media graph state for streamon/off to the pipeline

[Mauro Carvalho Chehab <mchehab@osg.samsung.com>]

Em Tue, 27 Oct 2015 01:01:36 +0200
Sakari Ailus <sakari.ailus@iki.fi> escreveu:

> The struct media_entity_graph was allocated in the stack, limiting the
> number of entities that could be reasonably allocated. Instead, move the
> struct to struct media_pipeline which is typically allocated using
> kmalloc() instead.
> 
> The intent is to keep the enumeration around for later use for the
> duration of the streaming. As streaming is eventually stopped, an
> unfortunate memory allocation failure would prevent stopping the
> streaming. As no memory will need to be allocated, the problem is avoided
> altogether.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/media-entity.c | 16 ++++++++--------
>  include/media/media-entity.h |  2 ++
>  2 files changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
> index fceaf44..667ab32 100644
> --- a/drivers/media/media-entity.c
> +++ b/drivers/media/media-entity.c
> @@ -456,16 +456,16 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
>  					     struct media_pipeline *pipe)
>  {
>  	struct media_device *mdev = entity->graph_obj.mdev;
> -	struct media_entity_graph graph;
> +	struct media_entity_graph *graph = &pipe->graph;
>  	struct media_entity *entity_err = entity;
>  	struct media_link *link;
>  	int ret;
>  
>  	mutex_lock(&mdev->graph_mutex);
>  
> -	media_entity_graph_walk_start(&graph, entity);
> +	media_entity_graph_walk_start(graph, entity);
>  
> -	while ((entity = media_entity_graph_walk_next(&graph))) {
> +	while ((entity = media_entity_graph_walk_next(graph))) {
>  		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
>  		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
>  
> @@ -546,9 +546,9 @@ error:
>  	 * Link validation on graph failed. We revert what we did and
>  	 * return the error.
>  	 */
> -	media_entity_graph_walk_start(&graph, entity_err);
> +	media_entity_graph_walk_start(graph, entity_err);
>  
> -	while ((entity_err = media_entity_graph_walk_next(&graph))) {
> +	while ((entity_err = media_entity_graph_walk_next(graph))) {
>  		entity_err->stream_count--;
>  		if (entity_err->stream_count == 0)
>  			entity_err->pipe = NULL;
> @@ -582,13 +582,13 @@ EXPORT_SYMBOL_GPL(media_entity_pipeline_start);
>  void media_entity_pipeline_stop(struct media_entity *entity)
>  {
>  	struct media_device *mdev = entity->graph_obj.mdev;
> -	struct media_entity_graph graph;
> +	struct media_entity_graph *graph = &entity->pipe->graph;
>  
>  	mutex_lock(&mdev->graph_mutex);
>  
> -	media_entity_graph_walk_start(&graph, entity);
> +	media_entity_graph_walk_start(graph, entity);
>  
> -	while ((entity = media_entity_graph_walk_next(&graph))) {
> +	while ((entity = media_entity_graph_walk_next(graph))) {
>  		entity->stream_count--;
>  		if (entity->stream_count == 0)
>  			entity->pipe = NULL;
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index dde9a5f..b2864cb 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -98,6 +98,8 @@ struct media_entity_graph {
>  };
>  
>  struct media_pipeline {
> +	/* For walking the graph in pipeline start / stop */
> +	struct media_entity_graph graph;
>  };

Please use the kernel-doc format for documenting struct.

After this change:

Reviewed-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>  
>  /**


-- 

Cheers,
Mauro