[media] media-device: check before unregister if mdev was registered

Most media functions that unregister, check if the corresponding register
function succeed before. So these functions can safely be called even if a
registration was never made or the component as already been unregistered.

Add the same check to media_device_unregister() function for consistency.

This will also allow to split the media_device_register() function in an
initialization and registration functions without the need to change the
generic cleanup functions and error code paths for all the media drivers.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Javier Martinez Canillas 2015-12-11 20:57:07 -02:00 committed by Mauro Carvalho Chehab
parent cc4a82581c
commit 223d19c566

View file

@ -577,6 +577,8 @@ EXPORT_SYMBOL_GPL(__media_device_register);
* media_device_unregister - unregister a media device
* @mdev: The media device
*
* It is safe to call this function on an unregistered
* (but initialised) media device.
*/
void media_device_unregister(struct media_device *mdev)
{
@ -584,6 +586,10 @@ void media_device_unregister(struct media_device *mdev)
struct media_entity *next;
struct media_interface *intf, *tmp_intf;
/* Check if mdev was ever registered at all */
if (!media_devnode_is_registered(&mdev->devnode))
return;
/* Remove all entities from the media device */
list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
media_device_unregister_entity(entity);