The G_TOPOLOGY ioctl is used to get a graph topology and since in the future a graph can be dynamically updated, there is a way to know the topology version so userspace can be aware that the graph has changed. The version 0 is reserved to indicate that the graph is static (i.e no graphs updates since the media device was registered). So, now that the media device initialization and registration has been split and the media device node is not exposed to user-space until all the entities have been registered and links created, it is safe to set a topology version 0 in media_device_register(). Suggested-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx> Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> --- Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None drivers/media/media-device.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index 5d5c8a57e7ba..d166cf5ad3ff 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -581,6 +581,10 @@ int __must_check __media_device_register(struct media_device *mdev, mdev->devnode.fops = &media_device_fops; mdev->devnode.parent = mdev->dev; mdev->devnode.release = media_device_release; + + /* Set version 0 to indicate user-space that the graph is static */ + mdev->topology_version = 0; + ret = media_devnode_register(&mdev->devnode, owner); if (ret < 0) return ret; -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
