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| author | Sakari Ailus <sakari.ailus@linux.intel.com> | 2021-03-12 10:05:44 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2021-04-06 14:35:14 +0200 |
| commit | 4ebddb7c17c4549f04741c7faf8e4ced62391d20 (patch) | |
| tree | 928c1a767c599fc03e08e0b641877ca3e8ab1353 | |
| parent | 5bf2c8b66e4eb47f16ce41b936be699d07256b76 (diff) | |
| download | linux-4ebddb7c17c4549f04741c7faf8e4ced62391d20.tar.bz2 | |
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>
| -rw-r--r-- | drivers/media/mc/mc-entity.c | 1 | ||||
| -rw-r--r-- | include/media/media-entity.h | 5 |
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c index 12b45e669bcc..678b99771cfa 100644 --- a/drivers/media/mc/mc-entity.c +++ b/drivers/media/mc/mc-entity.c @@ -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) diff --git a/include/media/media-entity.h b/include/media/media-entity.h index a90e2bf6baf7..09737b47881f 100644 --- a/include/media/media-entity.h +++ b/include/media/media-entity.h @@ -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); |