[PATCH v3 08/22] media: Media Controller non-locking __media_entity_pipeline_start/stop()

Shuah Khan
2016-02-11T23:42:11Z

Add non-locking __media_entity_pipeline_start/stop()
interfaces to be called from code paths that hold the
graph_mutex.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
drivers/media/media-entity.c | 34 ++++++++++++++++++++++++----------
include/media/media-entity.h | 19 +++++++++++++++++++
2 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 9b4d712..b78e4c2 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -365,8 +365,8 @@ EXPORT_SYMBOL_GPL(media_entity_graph_walk_next);
* Pipeline management
*/

-__must_check int media_entity_pipeline_start(struct media_entity *entity,
- struct media_pipeline *pipe)
+__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 = &pipe->graph;
@@ -374,8 +374,6 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
struct media_link *link;
int ret;

- mutex_lock(&mdev->graph_mutex);
-
if (!pipe->streaming_count++) {
ret = media_entity_graph_walk_init(&pipe->graph, mdev);
if (ret)
@@ -456,8 +454,6 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
}
}

- mutex_unlock(&mdev->graph_mutex);
-
return 0;

error:
@@ -487,19 +483,28 @@ error_graph_walk_start:
if (!--pipe->streaming_count)
media_entity_graph_walk_cleanup(graph);

- mutex_unlock(&mdev->graph_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__media_entity_pipeline_start);

+__must_check int media_entity_pipeline_start(struct media_entity *entity,
+ struct media_pipeline *pipe)
+{
+ struct media_device *mdev = entity->graph_obj.mdev;
+ int ret;
+
+ mutex_lock(&mdev->graph_mutex);
+ ret = __media_entity_pipeline_start(entity, pipe);
+ mutex_unlock(&mdev->graph_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(media_entity_pipeline_start);

-void media_entity_pipeline_stop(struct media_entity *entity)
+void __media_entity_pipeline_stop(struct media_entity *entity)
{
- struct media_device *mdev = entity->graph_obj.mdev;
struct media_entity_graph *graph = &entity->pipe->graph;
struct media_pipeline *pipe = entity->pipe;

- mutex_lock(&mdev->graph_mutex);

WARN_ON(!pipe->streaming_count);
media_entity_graph_walk_start(graph, entity);
@@ -516,6 +521,15 @@ void media_entity_pipeline_stop(struct media_entity *entity)
if (!--pipe->streaming_count)
media_entity_graph_walk_cleanup(graph);

+}
+EXPORT_SYMBOL_GPL(__media_entity_pipeline_stop);
+
+void media_entity_pipeline_stop(struct media_entity *entity)
+{
+ struct media_device *mdev = entity->graph_obj.mdev;
+
+ mutex_lock(&mdev->graph_mutex);
+ __media_entity_pipeline_stop(entity);
mutex_unlock(&mdev->graph_mutex);
}
EXPORT_SYMBOL_GPL(media_entity_pipeline_stop);
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index fe485d3..d58e29d 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -832,6 +832,16 @@ media_entity_graph_walk_next(struct media_entity_graph *graph);
*/
__must_check int media_entity_pipeline_start(struct media_entity *entity,
struct media_pipeline *pipe);
+/**
+ * __media_entity_pipeline_start - Mark a pipeline as streaming
+ *
+ * @entity: Starting entity
+ * @pipe: Media pipeline to be assigned to all entities in the pipeline.
+ *
+ * Note: This is the non-locking version of media_entity_pipeline_start()
+ */
+__must_check int __media_entity_pipeline_start(struct media_entity *entity,
+ struct media_pipeline *pipe);

/**
* media_entity_pipeline_stop - Mark a pipeline as not streaming
@@ -848,6 +858,15 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
void media_entity_pipeline_stop(struct media_entity *entity);

/**
+ * __media_entity_pipeline_stop - Mark a pipeline as not streaming
+ *
+ * @entity: Starting entity
+ *
+ * Note: This is the non-locking version of media_entity_pipeline_stop()
+ */
+void __media_entity_pipeline_stop(struct media_entity *entity);
+
+/**
* media_devnode_create() - creates and initializes a device node interface
*
* @mdev: pointer to struct &media_device
--
2.5.0