Re: [PATCH v6 7/8] [media] media: add a debug message to warn about gobj creation/removal

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

Hi Mauro,

Thank you for the patch.

On Wednesday 19 August 2015 08:01:54 Mauro Carvalho Chehab wrote:
> It helps to check if the media controller is doing the
> right thing with the object creation and removal.
> 
> No extra code/data will be produced if DEBUG or
> CONFIG_DYNAMIC_DEBUG is not enabled.

CONFIG_DYNAMIC_DEBUG is often enabled.

You're more or less adding function call tracing in this patch, isn't that 
something that ftrace is supposed to do ?

> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> 
> diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
> index 36d725ec5f3d..6d515e149d7f 100644
> --- a/drivers/media/media-entity.c
> +++ b/drivers/media/media-entity.c
> @@ -27,6 +27,69 @@
>  #include <media/media-device.h>
> 
>  /**
> + *  dev_dbg_obj - Prints in debug mode a change on some object
> + *
> + * @event_name:	Name of the event to report. Could be __func__
> + * @gobj:	Pointer to the object
> + *
> + * Enabled only if DEBUG or CONFIG_DYNAMIC_DEBUG. Otherwise, it
> + * won't produce any code.
> + */
> +static inline const char *gobj_type(enum media_gobj_type type)
> +{
> +	switch (type) {
> +	case MEDIA_GRAPH_ENTITY:
> +		return "entity";
> +	case MEDIA_GRAPH_PAD:
> +		return "pad";
> +	case MEDIA_GRAPH_LINK:
> +		return "link";
> +	default:
> +		return "unknown";
> +	}
> +}
> +
> +static void dev_dbg_obj(const char *event_name,  struct media_gobj *gobj)
> +{
> +#if defined(DEBUG) || defined (CONFIG_DYNAMIC_DEBUG)
> +	switch (media_type(gobj)) {
> +	case MEDIA_GRAPH_ENTITY:
> +		dev_dbg(gobj->mdev->dev,
> +			"%s: id 0x%08x entity#%d: '%s'\n",
> +			event_name, gobj->id, media_localid(gobj),
> +			gobj_to_entity(gobj)->name);
> +		break;
> +	case MEDIA_GRAPH_LINK:
> +	{
> +		struct media_link *link = gobj_to_link(gobj);
> +
> +		dev_dbg(gobj->mdev->dev,
> +			"%s: id 0x%08x link#%d: '%s' %s#%d ==> '%s' %s#%d\n",
> +			event_name, gobj->id, media_localid(gobj),
> +
> +			link->source->entity->name,
> +			gobj_type(media_type(&link->source->graph_obj)),
> +			media_localid(&link->source->graph_obj),
> +
> +			link->sink->entity->name,
> +			gobj_type(media_type(&link->sink->graph_obj)),
> +			media_localid(&link->sink->graph_obj));
> +		break;
> +	}
> +	case MEDIA_GRAPH_PAD:
> +	{
> +		struct media_pad *pad = gobj_to_pad(gobj);
> +
> +		dev_dbg(gobj->mdev->dev,
> +			"%s: id 0x%08x pad#%d: '%s':%d\n",
> +			event_name, gobj->id, media_localid(gobj),
> +			pad->entity->name, pad->index);
> +	}
> +	}
> +#endif
> +}
> +
> +/**
>   *  media_gobj_init - Initialize a graph object
>   *
>   * @mdev:	Pointer to the media_device that contains the object
> @@ -43,6 +106,8 @@ void media_gobj_init(struct media_device *mdev,
>  			   enum media_gobj_type type,
>  			   struct media_gobj *gobj)
>  {
> +	gobj->mdev = mdev;
> +
>  	/* Create a per-type unique object ID */
>  	switch (type) {
>  	case MEDIA_GRAPH_ENTITY:
> @@ -55,6 +120,7 @@ void media_gobj_init(struct media_device *mdev,
>  		gobj->id = media_gobj_gen_id(type, ++mdev->link_id);
>  		break;
>  	}
> +	dev_dbg_obj(__func__, gobj);
>  }
> 
>  /**
> @@ -66,7 +132,7 @@ void media_gobj_init(struct media_device *mdev,
>   */
>  void media_gobj_remove(struct media_gobj *gobj)
>  {
> -	/* For now, nothing to do */
> +	dev_dbg_obj(__func__, gobj);
>  }
> 
>  /**
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index 749b46c91217..bdd5e565ae76 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -61,6 +61,7 @@ enum media_gobj_type {
>   * All elements on the media graph should have this struct embedded
>   */
>  struct media_gobj {
> +	struct media_device	*mdev;

I'd move this to the patch that introduces media_gobj.

>  	u32			id;
>  };
> 
> @@ -192,6 +193,12 @@ struct media_entity_graph {
>  #define gobj_to_entity(gobj) \
>  		container_of(gobj, struct media_entity, graph_obj)
> 
> +#define gobj_to_pad(gobj) \
> +		container_of(gobj, struct media_pad, graph_obj)
> +
> +#define gobj_to_link(gobj) \
> +		container_of(gobj, struct media_link, graph_obj)
> +

And I'd call these media_gobj_* as commented on patch 2/8.

>  void media_gobj_init(struct media_device *mdev,
>  		    enum media_gobj_type type,
>  		    struct media_gobj *gobj);

-- 
Regards,

Laurent Pinchart