Add a note at the headers telling that the link setup
callbacks are called with the mutex hold. Also, removes a
double lock at the PM suspend callbacks.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
---
drivers/media/media-device.c | 1 -
drivers/media/v4l2-core/v4l2-mc.c | 4 ----
include/media/media-device.h | 3 ++-
include/media/media-entity.h | 3 +++
4 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 6cfa890af7b4..6af5e6932271 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -93,7 +93,6 @@ static struct media_entity *find_entity(struct media_device *mdev, u32 id)
media_device_for_each_entity(entity, mdev) {
if (((media_entity_id(entity) == id) && !next) ||
((media_entity_id(entity) > id) && next)) {
- mutex_unlock(&mdev->graph_mutex);
return entity;
}
}
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 2228cd3a846e..d44ff2ec314f 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -348,8 +348,6 @@ int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
int change = use ? 1 : -1;
int ret;
- mutex_lock(&mdev->graph_mutex);
-
/* Apply use count to node. */
entity->use_count += change;
WARN_ON(entity->use_count < 0);
@@ -359,8 +357,6 @@ int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
if (ret < 0)
entity->use_count -= change;
- mutex_unlock(&mdev->graph_mutex);
-
return ret;
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
diff --git a/include/media/media-device.h b/include/media/media-device.h
index b04cfa907350..e6ad30c323fc 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -312,7 +312,8 @@ struct media_entity_notify {
* @enable_source: Enable Source Handler function pointer
* @disable_source: Disable Source Handler function pointer
*
- * @link_notify: Link state change notification callback
+ * @link_notify: Link state change notification callback. This callback is
+ * Called with the graph_mutex hold.
*
* This structure represents an abstract high-level media device. It allows easy
* access to entities and provides basic media device-level support. The
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 6dc9e4e8cbd4..0b16ebe36db7 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -179,6 +179,9 @@ struct media_pad {
* @link_validate: Return whether a link is valid from the entity point of
* view. The media_entity_pipeline_start() function
* validates all links by calling this operation. Optional.
+ *
+ * Note: Those ioctls should not touch the struct media_device.@graph_mutex
+ * field, as they're called with it already hold.
*/
struct media_entity_operations {
int (*link_setup)(struct media_entity *entity,
--
2.5.5
--
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