Add non-locking __media_entity_pipeline_start/stop() interfaces
to be called from code paths that hold the graph_mutex. For this
change, the media_entity_pipeline_start() routine is renamed to
__media_entity_pipeline_start() minus the graph_mutex lock and
unlock. media_entity_pipeline_start() now calls the non-locking
__media_entity_pipeline_start() holding the graph_lock. The stop
interface, media_entity_pipeline_stop() routine is renamed to
__media_entity_pipeline_stop() minus the graph_mutex lock and
unlock. media_entity_pipeline_stop() now calls the non-locking
__media_entity_pipeline_stop() holding the graph_lock.
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
---
drivers/media/media-entity.c | 34 ++++++++++++++++++++++++----------
include/media/media-entity.h | 12 ++++++++++++
2 files changed, 36 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..c7583db 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -832,6 +832,12 @@ 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);
+/**
+ * non-locking __media_entity_pipeline_start() can be called from
+ * code paths that hold the graph_mutex
+ */
+__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 +854,12 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
void media_entity_pipeline_stop(struct media_entity *entity);
/**
+ * non-locking __media_entity_pipeline_stop() can be called from
+ * code paths that hold the graph_mutex
+ */
+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
--
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