Re: [PATCH 02/19] media: Introduce internal index for media entities

From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
To: Sakari Ailus <sakari.ailus@iki.fi>
Cc: linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com,
	javier@osg.samsung.com, hverkuil@xs4all.nl,
	Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: Re: [PATCH 02/19] media: Introduce internal index for media entities
Date: Wed, 28 Oct 2015 09:20:20 +0900	[thread overview]
Message-ID: <20151028092020.33a1e509@concha.lan> (raw)
In-Reply-To: <1445900510-1398-3-git-send-email-sakari.ailus@iki.fi>

Em Tue, 27 Oct 2015 01:01:33 +0200
Sakari Ailus <sakari.ailus@iki.fi> escreveu:

> From: Sakari Ailus <sakari.ailus@linux.intel.com>
> 
> The internal index can be used internally by the framework in order to keep
> track of entities for a purpose or another. The internal index is constant
> while it's registered to a media device, but the same index may be re-used
> once the entity having that index is unregistered.

Reviewed-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/media-device.c | 17 +++++++++++++++++
>  include/media/media-device.h |  4 ++++
>  include/media/media-entity.h |  3 +++
>  3 files changed, 24 insertions(+)
> 
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index c181758..ebb84cb 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -22,6 +22,7 @@
>  
>  #include <linux/compat.h>
>  #include <linux/export.h>
> +#include <linux/idr.h>
>  #include <linux/ioctl.h>
>  #include <linux/media.h>
>  #include <linux/types.h>
> @@ -546,6 +547,7 @@ void media_device_init(struct media_device *mdev)
>  	INIT_LIST_HEAD(&mdev->links);
>  	spin_lock_init(&mdev->lock);
>  	mutex_init(&mdev->graph_mutex);
> +	ida_init(&mdev->entity_internal_idx);
>  
>  	dev_dbg(mdev->dev, "Media device initialized\n");
>  }
> @@ -558,6 +560,8 @@ EXPORT_SYMBOL_GPL(media_device_init);
>   */
>  void media_device_cleanup(struct media_device *mdev)
>  {
> +	ida_destroy(&mdev->entity_internal_idx);
> +	mdev->entity_internal_idx_max = 0;
>  	mutex_destroy(&mdev->graph_mutex);
>  }
>  EXPORT_SYMBOL_GPL(media_device_cleanup);
> @@ -658,6 +662,17 @@ int __must_check media_device_register_entity(struct media_device *mdev,
>  	INIT_LIST_HEAD(&entity->links);
>  
>  	spin_lock(&mdev->lock);
> +
> +	entity->internal_idx = ida_simple_get(&mdev->entity_internal_idx, 1, 0,
> +					      GFP_KERNEL);
> +	if (entity->internal_idx < 0) {
> +		spin_unlock(&mdev->lock);
> +		return entity->internal_idx;
> +	}
> +
> +	mdev->entity_internal_idx_max =
> +		max(mdev->entity_internal_idx_max, entity->internal_idx);
> +
>  	/* Initialize media_gobj embedded at the entity */
>  	media_gobj_init(mdev, MEDIA_GRAPH_ENTITY, &entity->graph_obj);
>  
> @@ -690,6 +705,8 @@ void media_device_unregister_entity(struct media_entity *entity)
>  
>  	spin_lock(&mdev->lock);
>  
> +	ida_simple_remove(&mdev->entity_internal_idx, entity->internal_idx);
> +
>  	/* Remove interface links with this entity on it */
>  	list_for_each_entry_safe(link, tmp, &mdev->links, graph_obj.list) {
>  		if (media_type(link->gobj1) == MEDIA_GRAPH_ENTITY
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index a2c7570..c0e1764 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -30,6 +30,7 @@
>  #include <media/media-devnode.h>
>  #include <media/media-entity.h>
>  
> +struct ida;
>  struct device;
>  
>  /**
> @@ -47,6 +48,7 @@ struct device;
>   * @pad_id:	Unique ID used on the last pad registered
>   * @link_id:	Unique ID used on the last link registered
>   * @intf_devnode_id: Unique ID used on the last interface devnode registered
> + * @entity_internal_idx: Allocated internal entity indices
>   * @entities:	List of registered entities
>   * @interfaces:	List of registered interfaces
>   * @pads:	List of registered pads
> @@ -82,6 +84,8 @@ struct media_device {
>  	u32 pad_id;
>  	u32 link_id;
>  	u32 intf_devnode_id;
> +	struct ida entity_internal_idx;
> +	int entity_internal_idx_max;
>  
>  	struct list_head entities;
>  	struct list_head interfaces;
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index eebdd24..d3d3a39 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -159,6 +159,8 @@ struct media_entity_operations {
>   * @num_pads:	Number of sink and source pads.
>   * @num_links:	Number of existing links, both enabled and disabled.
>   * @num_backlinks: Number of backlinks
> + * @internal_idx: An unique internal entity specific number. The numbers are
> + *		re-used if entities are unregistered or registered again.
>   * @pads:	Pads array with the size defined by @num_pads.
>   * @links:	Linked list for the data links.
>   * @ops:	Entity operations.
> @@ -187,6 +189,7 @@ struct media_entity {
>  	u16 num_pads;
>  	u16 num_links;
>  	u16 num_backlinks;
> +	int internal_idx;
>  
>  	struct media_pad *pads;
>  	struct list_head links;


-- 

Cheers,
Mauro