Re: [PATCH v6 3/8] [media] media: use media_gobj inside entities

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Mauro,

Thank you for the patch.

On Wednesday 19 August 2015 08:01:50 Mauro Carvalho Chehab wrote:
> As entities are graph elements, let's embed media_gobj
> on it. That ensures an unique ID for entities that can be
> global along the entire media controller.
> 
> For now, we'll keep the already existing entity ID. Such
> field need to be dropped at some point, but for now, let's
> not do this, to avoid needing to review all drivers and
> the userspace apps.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> 
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index e429605ca2c3..81d6a130efef 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -379,7 +379,6 @@ int __must_check __media_device_register(struct
> media_device *mdev, if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
>  		return -EINVAL;
> 
> -	mdev->entity_id = 1;
>  	INIT_LIST_HEAD(&mdev->entities);
>  	spin_lock_init(&mdev->lock);
>  	mutex_init(&mdev->graph_mutex);
> @@ -433,10 +432,8 @@ int __must_check media_device_register_entity(struct
> media_device *mdev, entity->parent = mdev;
> 
>  	spin_lock(&mdev->lock);
> -	if (entity->id == 0)
> -		entity->id = mdev->entity_id++;
> -	else
> -		mdev->entity_id = max(entity->id + 1, mdev->entity_id);
> +	/* Initialize media_gobj embedded at the entity */
> +	media_gobj_init(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);

Graph object initialization should be moved to media_entity_init() to keep 
initialization separate from registration.

>  	list_add_tail(&entity->list, &mdev->entities);
>  	spin_unlock(&mdev->lock);
> 
> @@ -459,6 +456,7 @@ void media_device_unregister_entity(struct media_entity
> *entity) return;
> 
>  	spin_lock(&mdev->lock);
> +	media_gobj_remove(&entity->graph_obj);
>  	list_del(&entity->list);
>  	spin_unlock(&mdev->lock);
>  	entity->parent = NULL;
> diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
> index 4834172bf6f8..888cb88e19bf 100644
> --- a/drivers/media/media-entity.c
> +++ b/drivers/media/media-entity.c
> @@ -43,7 +43,12 @@ void media_gobj_init(struct media_device *mdev,
>  			   enum media_gobj_type type,
>  			   struct media_gobj *gobj)
>  {
> -	/* For now, nothing to do */
> +	/* Create a per-type unique object ID */
> +	switch (type) {
> +	case MEDIA_GRAPH_ENTITY:
> +		gobj->id = media_gobj_gen_id(type, ++mdev->entity_id);
> +		break;
> +	}
>  }
> 
>  /**
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index a44f18fdf321..f6deef6e5820 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -41,7 +41,7 @@ struct device;
>   * @bus_info:	Unique and stable device location identifier
>   * @hw_revision: Hardware device revision
>   * @driver_version: Device driver version
> - * @entity_id:	ID of the next entity to be registered
> + * @entity_id:	Unique ID used on the last entity registered
>   * @entities:	List of registered entities
>   * @lock:	Entities list lock
>   * @graph_mutex: Entities graph operation lock
> @@ -69,6 +69,7 @@ struct media_device {
>  	u32 driver_version;
> 
>  	u32 entity_id;
> +
>  	struct list_head entities;
> 
>  	/* Protects the entities list */
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index c1cd4fba051d..9ca366334bcf 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -33,10 +33,10 @@
>  /**
>   * enum media_gobj_type - type of a graph element
>   *
> + * @MEDIA_GRAPH_ENTITY:		Identify a media entity

I think we should explicitly define here what an entity is.

>   */
>  enum media_gobj_type {
> -	 /* FIXME: add the types here, as we embed media_gobj */
> -	MEDIA_GRAPH_NONE
> +	MEDIA_GRAPH_ENTITY,
>  };
> 
>  #define MEDIA_BITS_PER_TYPE		8
> @@ -94,10 +94,9 @@ struct media_entity_operations {
>  };
> 
>  struct media_entity {
> +	struct media_gobj graph_obj;
>  	struct list_head list;
>  	struct media_device *parent;	/* Media device this entity belongs to*/
> -	u32 id;				/* Entity ID, unique in the parent media
> -					 * device context */
>  	const char *name;		/* Entity name */
>  	u32 type;			/* Entity type (MEDIA_ENT_T_*) */
>  	u32 revision;			/* Entity revision, driver specific */
> @@ -148,7 +147,7 @@ static inline u32 media_entity_subtype(struct
> media_entity *entity)
> 
>  static inline u32 media_entity_id(struct media_entity *entity)
>  {
> -	return entity->id;
> +	return entity->graph_obj.id;
>  }
> 
>  static inline enum media_gobj_type media_type(struct media_gobj *gobj)

-- 
Regards,

Laurent Pinchart