diff options
| author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2010-03-07 19:04:59 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-03-22 08:53:12 +0100 |
| commit | 503c3d829eaf48837dd5bff5d97ad66369bb955a (patch) | |
| tree | 9c14ed9561c5ffca07909e53d5ae0e52cdf5f99e /drivers/media/media-device.c | |
| parent | [media] media: Entity graph traversal (diff) | |
| download | linux-503c3d829eaf48837dd5bff5d97ad66369bb955a.tar.xz linux-503c3d829eaf48837dd5bff5d97ad66369bb955a.zip | |
[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 'drivers/media/media-device.c')
| -rw-r--r-- | drivers/media/media-device.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index a36509a1df09..d2bc809d7a2a 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -73,6 +73,7 @@ int __must_check media_device_register(struct media_device *mdev) mdev->entity_id = 1; INIT_LIST_HEAD(&mdev->entities); spin_lock_init(&mdev->lock); + mutex_init(&mdev->graph_mutex); /* Register the device node. */ mdev->devnode.fops = &media_device_fops; |