hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

media: entity: Add lockdep check to media graph walk 

It was always assumed that walking the media graph would require holding
the media_device graph_mutex but this was not documented nor checked for.

Add a lockdep check to graph walk init and iter, and document the need for
acquiring the graph_mutex.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Sakari Ailus 2021-03-12 10:05:44 +01:00 committed by Mauro Carvalho Chehab
parent 5bf2c8b66e
commit 4ebddb7c17
2 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/media/mc/mc-entity.c
View File

@ -340,6 +340,7 @@ static void media_graph_walk_iter(struct media_graph *graph)
stack_push(graph, next);
dev_dbg(entity->graph_obj.mdev->dev, "walk: pushing '%s' on stack\n",
next->name);
lockdep_assert_held(&entity->graph_obj.mdev->graph_mutex);
}
struct media_entity *media_graph_walk_next(struct media_graph *graph)

5
include/media/media-entity.h
View File

@ -885,6 +885,11 @@ int media_entity_get_fwnode_pad(struct media_entity *entity,
*
* @graph: Media graph structure that will be used to walk the graph
* @mdev: Pointer to the &media_device that contains the object
*
* The caller is required to hold the media_device graph_mutex during the graph
* walk until the graph state is released.
*
* Returns zero on success or a negative error code otherwise.
*/
__must_check int media_graph_walk_init(
struct media_graph *graph, struct media_device *mdev);