[v3,1/4] media: mc-entity.c: add media_graph_walk_next_stream()
diff mbox series

Message ID 20200415013044.1778572-2-helen.koike@collabora.com
State New
Headers show
Series
  • media: add v4l2_pipeline_stream_{enable, disable} helpers
Related show

Commit Message

Helen Koike April 15, 2020, 1:30 a.m. UTC
Add media_graph_walk_next_stream() function to follow links only from
sink to source (not the opposite) to allow iteration only through the
entities participating in a given stream.

This is useful to allow calling .s_stream() callback only in the
subdevices that requires to be enabled/disabled, and avoid calling this
callback when not required.

Signed-off-by: Helen Koike <helen.koike@collabora.com>

---

Changes in v3:
- Patch re-added in the series from version 1

Changes in v2: None

 drivers/media/mc/mc-entity.c | 34 +++++++++++++++++++++++++++++++---
 include/media/media-entity.h | 15 +++++++++++++++
 2 files changed, 46 insertions(+), 3 deletions(-)

Comments

Niklas Söderlund April 24, 2020, 1:46 p.m. UTC | #1
Hi Helen,

Thanks for your work.

On 2020-04-14 22:30:41 -0300, Helen Koike wrote:
> Add media_graph_walk_next_stream() function to follow links only from
> sink to source (not the opposite) to allow iteration only through the
> entities participating in a given stream.
> 
> This is useful to allow calling .s_stream() callback only in the
> subdevices that requires to be enabled/disabled, and avoid calling this
> callback when not required.
> 
> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> 
> ---
> 
> Changes in v3:
> - Patch re-added in the series from version 1
> 
> Changes in v2: None
> 
>  drivers/media/mc/mc-entity.c | 34 +++++++++++++++++++++++++++++++---
>  include/media/media-entity.h | 15 +++++++++++++++
>  2 files changed, 46 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> index 211279c5fd77d..0d44c2de23e6f 100644
> --- a/drivers/media/mc/mc-entity.c
> +++ b/drivers/media/mc/mc-entity.c
> @@ -228,6 +228,11 @@ EXPORT_SYMBOL_GPL(media_entity_pads_init);
>   * Graph traversal
>   */
>  
> +enum media_graph_walk_type {
> +	MEDIA_GRAPH_WALK_CONNECTED_NODES,
> +	MEDIA_GRAPH_WALK_STREAM_NODES,
> +};
> +
>  static struct media_entity *
>  media_entity_other(struct media_entity *entity, struct media_link *link)
>  {
> @@ -305,7 +310,8 @@ void media_graph_walk_start(struct media_graph *graph,
>  }
>  EXPORT_SYMBOL_GPL(media_graph_walk_start);
>  
> -static void media_graph_walk_iter(struct media_graph *graph)
> +static void media_graph_walk_iter(struct media_graph *graph,
> +				  enum media_graph_walk_type type)
>  {
>  	struct media_entity *entity = stack_top(graph);
>  	struct media_link *link;
> @@ -326,6 +332,15 @@ static void media_graph_walk_iter(struct media_graph *graph)
>  	/* Get the entity in the other end of the link . */
>  	next = media_entity_other(entity, link);
>  
> +	if (type == MEDIA_GRAPH_WALK_STREAM_NODES
> +	    && next == link->sink->entity) {
> +		link_top(graph) = link_top(graph)->next;
> +		dev_dbg(entity->graph_obj.mdev->dev,
> +			"walk: skipping '%s' (outside of the stream path)\n",
> +			link->sink->entity->name);
> +		return;
> +	}
> +
>  	/* Has the entity already been visited? */
>  	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
>  		link_top(graph) = link_top(graph)->next;
> @@ -342,7 +357,9 @@ static void media_graph_walk_iter(struct media_graph *graph)
>  		next->name);
>  }
>  
> -struct media_entity *media_graph_walk_next(struct media_graph *graph)
> +static struct media_entity *
> +__media_graph_walk_next(struct media_graph *graph,
> +			enum media_graph_walk_type type)
>  {
>  	struct media_entity *entity;
>  
> @@ -355,7 +372,7 @@ struct media_entity *media_graph_walk_next(struct media_graph *graph)
>  	 * found.
>  	 */
>  	while (link_top(graph) != &stack_top(graph)->links)
> -		media_graph_walk_iter(graph);
> +		media_graph_walk_iter(graph, type);
>  
>  	entity = stack_pop(graph);
>  	dev_dbg(entity->graph_obj.mdev->dev,
> @@ -363,8 +380,19 @@ struct media_entity *media_graph_walk_next(struct media_graph *graph)
>  
>  	return entity;
>  }
> +
> +struct media_entity *media_graph_walk_next(struct media_graph *graph)
> +{
> +	return __media_graph_walk_next(graph, MEDIA_GRAPH_WALK_CONNECTED_NODES);
> +}
>  EXPORT_SYMBOL_GPL(media_graph_walk_next);
>  
> +struct media_entity *media_graph_walk_next_stream(struct media_graph *graph)
> +{
> +	return __media_graph_walk_next(graph,  MEDIA_GRAPH_WALK_STREAM_NODES);

One space to much after the ','. With this fixed,

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> +}
> +EXPORT_SYMBOL_GPL(media_graph_walk_next_stream);
> +
>  int media_entity_get_fwnode_pad(struct media_entity *entity,
>  				struct fwnode_handle *fwnode,
>  				unsigned long direction_flags)
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index 8cb2c504a05c7..f17a5180ce524 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -927,6 +927,21 @@ void media_graph_walk_start(struct media_graph *graph,
>   */
>  struct media_entity *media_graph_walk_next(struct media_graph *graph);
>  
> +/**
> + * media_graph_walk_next_stream - Get the next entity in the graph
> + * @graph: Media graph structure
> + *
> + * Perform a depth-first traversal of the given media entities graph only
> + * following links from sink to source (and not the opposite).
> + *
> + * The graph structure must have been previously initialized with a call to
> + * media_graph_walk_start().
> + *
> + * Return: returns the next entity in the graph in the stream path
> + * or %NULL if the whole stream path have been traversed.
> + */
> +struct media_entity *media_graph_walk_next_stream(struct media_graph *graph);
> +
>  /**
>   * media_pipeline_start - Mark a pipeline as streaming
>   * @entity: Starting entity
> -- 
> 2.26.0
>

Patch
diff mbox series

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 211279c5fd77d..0d44c2de23e6f 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -228,6 +228,11 @@  EXPORT_SYMBOL_GPL(media_entity_pads_init);
  * Graph traversal
  */
 
+enum media_graph_walk_type {
+	MEDIA_GRAPH_WALK_CONNECTED_NODES,
+	MEDIA_GRAPH_WALK_STREAM_NODES,
+};
+
 static struct media_entity *
 media_entity_other(struct media_entity *entity, struct media_link *link)
 {
@@ -305,7 +310,8 @@  void media_graph_walk_start(struct media_graph *graph,
 }
 EXPORT_SYMBOL_GPL(media_graph_walk_start);
 
-static void media_graph_walk_iter(struct media_graph *graph)
+static void media_graph_walk_iter(struct media_graph *graph,
+				  enum media_graph_walk_type type)
 {
 	struct media_entity *entity = stack_top(graph);
 	struct media_link *link;
@@ -326,6 +332,15 @@  static void media_graph_walk_iter(struct media_graph *graph)
 	/* Get the entity in the other end of the link . */
 	next = media_entity_other(entity, link);
 
+	if (type == MEDIA_GRAPH_WALK_STREAM_NODES
+	    && next == link->sink->entity) {
+		link_top(graph) = link_top(graph)->next;
+		dev_dbg(entity->graph_obj.mdev->dev,
+			"walk: skipping '%s' (outside of the stream path)\n",
+			link->sink->entity->name);
+		return;
+	}
+
 	/* Has the entity already been visited? */
 	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
 		link_top(graph) = link_top(graph)->next;
@@ -342,7 +357,9 @@  static void media_graph_walk_iter(struct media_graph *graph)
 		next->name);
 }
 
-struct media_entity *media_graph_walk_next(struct media_graph *graph)
+static struct media_entity *
+__media_graph_walk_next(struct media_graph *graph,
+			enum media_graph_walk_type type)
 {
 	struct media_entity *entity;
 
@@ -355,7 +372,7 @@  struct media_entity *media_graph_walk_next(struct media_graph *graph)
 	 * found.
 	 */
 	while (link_top(graph) != &stack_top(graph)->links)
-		media_graph_walk_iter(graph);
+		media_graph_walk_iter(graph, type);
 
 	entity = stack_pop(graph);
 	dev_dbg(entity->graph_obj.mdev->dev,
@@ -363,8 +380,19 @@  struct media_entity *media_graph_walk_next(struct media_graph *graph)
 
 	return entity;
 }
+
+struct media_entity *media_graph_walk_next(struct media_graph *graph)
+{
+	return __media_graph_walk_next(graph, MEDIA_GRAPH_WALK_CONNECTED_NODES);
+}
 EXPORT_SYMBOL_GPL(media_graph_walk_next);
 
+struct media_entity *media_graph_walk_next_stream(struct media_graph *graph)
+{
+	return __media_graph_walk_next(graph,  MEDIA_GRAPH_WALK_STREAM_NODES);
+}
+EXPORT_SYMBOL_GPL(media_graph_walk_next_stream);
+
 int media_entity_get_fwnode_pad(struct media_entity *entity,
 				struct fwnode_handle *fwnode,
 				unsigned long direction_flags)
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 8cb2c504a05c7..f17a5180ce524 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -927,6 +927,21 @@  void media_graph_walk_start(struct media_graph *graph,
  */
 struct media_entity *media_graph_walk_next(struct media_graph *graph);
 
+/**
+ * media_graph_walk_next_stream - Get the next entity in the graph
+ * @graph: Media graph structure
+ *
+ * Perform a depth-first traversal of the given media entities graph only
+ * following links from sink to source (and not the opposite).
+ *
+ * The graph structure must have been previously initialized with a call to
+ * media_graph_walk_start().
+ *
+ * Return: returns the next entity in the graph in the stream path
+ * or %NULL if the whole stream path have been traversed.
+ */
+struct media_entity *media_graph_walk_next_stream(struct media_graph *graph);
+
 /**
  * media_pipeline_start - Mark a pipeline as streaming
  * @entity: Starting entity