diff options
| author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2010-03-07 15:04:59 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-03-22 04:53:12 -0300 |
| commit | 503c3d829eaf48837dd5bff5d97ad66369bb955a (patch) | |
| tree | 9c14ed9561c5ffca07909e53d5ae0e52cdf5f99e /include/media/media-device.h | |
| parent | a5ccc48a7c48610e7f92fa599406738d69195d51 (diff) | |
[media] media: Entity use count
Due to the wide differences between drivers regarding power management
needs, the media controller does not implement power management.
However, the media_entity structure includes a use_count field that
media drivers can use to track the number of users of every entity for
power management needs.
The use_count field is owned by media drivers and must not be touched by
entity drivers. Access to the field must be protected by the media
device graph_mutex lock.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'include/media/media-device.h')
| -rw-r--r-- | include/media/media-device.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/media/media-device.h b/include/media/media-device.h index a8390fe87e83..5d2bff4fc9e0 100644 --- a/include/media/media-device.h +++ b/include/media/media-device.h @@ -25,6 +25,7 @@ #include <linux/device.h> #include <linux/list.h> +#include <linux/mutex.h> #include <linux/spinlock.h> #include <media/media-devnode.h> @@ -42,6 +43,7 @@ * @entity_id: ID of the next entity to be registered * @entities: List of registered entities * @lock: Entities list lock + * @graph_mutex: Entities graph operation lock * * This structure represents an abstract high-level media device. It allows easy * access to entities and provides basic media device-level support. The @@ -69,6 +71,8 @@ struct media_device { /* Protects the entities list */ spinlock_t lock; + /* Serializes graph operations. */ + struct mutex graph_mutex; }; /* media_devnode to media_device */ |