From 223d19c56651a0204253035f9ed28834653d2b4b Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Fri, 11 Dec 2015 20:57:07 -0200 Subject: [PATCH] [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 Signed-off-by: Javier Martinez Canillas Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-device.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index ca16bd3091bd..da4126863ecc 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -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);