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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com,
	Jacopo Mondi <jacopo+renesas@jmondi.org>,
	niklas.soderlund+renesas@ragnatech.se,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>
Subject: Re: [PATCH v5 20/24] v4l: mc: Add an S_ROUTING helper function for power state changes
Date: Sun, 18 Apr 2021 21:55:40 +0300
Message-ID: <YHyArMhUhcamSf++@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20210415130450.421168-21-tomi.valkeinen@ideasonboard.com>

Hi Tomi and Sakari,

Thank you for the patch.

On Thu, Apr 15, 2021 at 04:04:46PM +0300, Tomi Valkeinen wrote:
> From: Sakari Ailus <sakari.ailus@linux.intel.com>
> 
> With the addition of the has_route() media entity operation, all pads of an
> entity are no longer interconnected. The S_ROUTING IOCTL for sub-devices can
> be used to enable and disable routes for an entity. The consequence is that
> the routing information has to be taken into account in use count
> calculation: disabling a route has a very similar effect on use counts as
> has disabling a link.
> 
> Add a helper function for drivers implementing VIDIOC_SUBDEV_S_ROUTING
> IOCTL to take the change into account.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/media/v4l2-core/v4l2-mc.c | 34 +++++++++++++++++++++++++++++++
>  include/media/v4l2-mc.h           | 22 ++++++++++++++++++++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
> index 35d18ed89fa5..71acb389aa7b 100644
> --- a/drivers/media/v4l2-core/v4l2-mc.c
> +++ b/drivers/media/v4l2-core/v4l2-mc.c
> @@ -588,3 +588,37 @@ int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);
> +
> +int v4l2_subdev_routing_pm_use(struct media_entity *entity,
> +			       struct v4l2_subdev_route *route)
> +{
> +	struct media_graph *graph =
> +		&entity->graph_obj.mdev->pm_count_walk;
> +	struct media_pad *source = &entity->pads[route->source_pad];
> +	struct media_pad *sink = &entity->pads[route->sink_pad];
> +	int source_use;
> +	int sink_use;
> +	int ret;
> +
> +	source_use = pipeline_pm_use_count(source, graph);
> +	sink_use = pipeline_pm_use_count(sink, graph);
> +
> +	if (!(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE)) {
> +		/* Route disabled. */
> +		pipeline_pm_power(source, -sink_use, graph);
> +		pipeline_pm_power(sink, -source_use, graph);
> +		return 0;
> +	}
> +
> +	/* Route enabled. */
> +	ret = pipeline_pm_power(source, sink_use, graph);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = pipeline_pm_power(sink, source_use, graph);
> +	if (ret < 0)
> +		pipeline_pm_power(source, -sink_use, graph);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_subdev_routing_pm_use);

.s_power() is getting deprecated for sensors. Sakari, should we move
away from pipeline-based power management and drop this patch, or is it
too early ?

> diff --git a/include/media/v4l2-mc.h b/include/media/v4l2-mc.h
> index c181685923d5..ab8f4dc143aa 100644
> --- a/include/media/v4l2-mc.h
> +++ b/include/media/v4l2-mc.h
> @@ -18,6 +18,7 @@
>  /* We don't need to include pci.h or usb.h here */
>  struct pci_dev;
>  struct usb_device;
> +struct v4l2_subdev_route;
>  
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  /**
> @@ -184,6 +185,22 @@ void v4l2_pipeline_pm_put(struct media_entity *entity);
>  int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
>  			      unsigned int notification);
>  
> +/**
> + * v4l2_subdev_routing_pm_use - Handle power state changes due to S_ROUTING
> + * @entity: The entity
> + * @route: The new state of the route
> + *
> + * Propagate the use count across a route in a pipeline whenever the
> + * route is enabled or disabled. The function is called before
> + * changing the route state when enabling a route, and after changing
> + * the route state when disabling a route.
> + *
> + * Return 0 on success or a negative error code on failure. Powering entities
> + * off is assumed to never fail. This function will not fail for disconnection
> + * events.

"disconnection events" make me think about hotplug. How about "will not
fail when disabling a route" ?

> + */
> +int v4l2_subdev_routing_pm_use(struct media_entity *entity,
> +			       struct v4l2_subdev_route *route);
>  #else /* CONFIG_MEDIA_CONTROLLER */
>  
>  static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
> @@ -219,5 +236,10 @@ static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
>  	return 0;
>  }
>  
> +static inline int v4l2_subdev_routing_pm_use(struct media_entity *entity,
> +					     struct v4l2_subdev_route *route)
> +{
> +	return 0;
> +}

Missing blank line.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

(assuming we want to keep the patch)

>  #endif /* CONFIG_MEDIA_CONTROLLER */
>  #endif /* _V4L2_MC_H */

-- 
Regards,

Laurent Pinchart

  reply index

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-15 13:04 [PATCH v5 00/24] v4l: subdev internal routing Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 01/24] media: entity: Use pad as a starting point for graph walk Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 02/24] media: entity: Use pads instead of entities in the media graph walk stack Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 03/24] media: entity: Walk the graph based on pads Tomi Valkeinen
2021-04-18 17:47   ` Laurent Pinchart
2021-04-20 11:30     ` Sakari Ailus
2021-04-15 13:04 ` [PATCH v5 04/24] v4l: mc: Start walk from a specific pad in use count calculation Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 05/24] media: entity: Add iterator helper for entity pads Tomi Valkeinen
2021-04-18 17:52   ` Laurent Pinchart
2021-04-22 12:04     ` Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 06/24] media: entity: Move the pipeline from entity to pads Tomi Valkeinen
2021-04-18 18:00   ` Laurent Pinchart
2021-04-20 11:38     ` Sakari Ailus
2021-04-15 13:04 ` [PATCH v5 07/24] media: entity: Use pad as the starting point for a pipeline Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 08/24] media: entity: Add has_route entity operation Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 09/24] media: entity: Add media_entity_has_route() function Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 10/24] media: entity: Use routing information during graph traversal Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 11/24] media: entity: Skip link validation for pads to which there is no route to Tomi Valkeinen
2021-04-18 18:06   ` Laurent Pinchart
2021-04-20 11:41     ` Sakari Ailus
2021-04-23 12:37       ` Tomi Valkeinen
2021-04-29 12:06         ` Sakari Ailus
2021-04-29 14:10           ` Laurent Pinchart
2021-04-15 13:04 ` [PATCH v5 12/24] media: entity: Add an iterator helper for connected pads Tomi Valkeinen
2021-04-18 18:20   ` Laurent Pinchart
2021-04-20 11:48     ` Sakari Ailus
2021-04-29  1:33       ` Laurent Pinchart
2021-04-29 11:56         ` Sakari Ailus
2021-04-29 12:04           ` Tomi Valkeinen
2021-04-29 12:07             ` Sakari Ailus
2021-04-29 12:14               ` Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 13/24] media: entity: Add only connected pads to the pipeline Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 14/24] media: entity: Add debug information in graph walk route check Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 15/24] v4l: Add bus type to frame descriptors Tomi Valkeinen
2021-04-18 19:23   ` Laurent Pinchart
2021-04-20 11:50     ` Sakari Ailus
2021-04-22 12:30       ` Tomi Valkeinen
2021-04-29 11:58         ` Sakari Ailus
2021-04-29 14:09           ` Laurent Pinchart
2021-04-15 13:04 ` [PATCH v5 16/24] v4l: Add CSI-2 bus configuration " Tomi Valkeinen
2021-04-18 19:24   ` Laurent Pinchart
2021-04-20 16:32     ` Sakari Ailus
2021-04-15 13:04 ` [PATCH v5 17/24] v4l: Add stream to frame descriptor Tomi Valkeinen
2021-04-18 19:27   ` Laurent Pinchart
2021-04-22 12:47     ` Tomi Valkeinen
2021-04-22 16:18       ` Laurent Pinchart
2021-04-15 13:04 ` [PATCH v5 18/24] v4l: subdev: Add [GS]_ROUTING subdev ioctls and operations Tomi Valkeinen
2021-04-18 18:32   ` Laurent Pinchart
2021-04-22 11:16     ` Tomi Valkeinen
2021-04-22 16:20       ` Laurent Pinchart
2021-04-22 16:58         ` Tomi Valkeinen
2021-04-20 16:35   ` Sakari Ailus
2021-04-15 13:04 ` [PATCH v5 19/24] media: Documentation: Add GS_ROUTING documentation Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 20/24] v4l: mc: Add an S_ROUTING helper function for power state changes Tomi Valkeinen
2021-04-18 18:55   ` Laurent Pinchart [this message]
2021-04-20 16:41     ` Sakari Ailus
2021-04-15 13:04 ` [PATCH v5 21/24] v4l: subdev: routing kernel helper functions Tomi Valkeinen
2021-04-18 19:18   ` Laurent Pinchart
2021-04-15 13:04 ` [PATCH v5 22/24] v4l: subdev: add v4l2_subdev_get_format_dir() Tomi Valkeinen
2021-04-18 19:04   ` Laurent Pinchart
2021-04-21 13:04     ` Tomi Valkeinen
2021-04-29  1:43       ` Laurent Pinchart
2021-05-04  6:49         ` Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 23/24] v4l: subdev: Take routing information into account in link validation Tomi Valkeinen
2021-04-15 13:04 ` [PATCH v5 24/24] v4l: subdev: increase V4L2_FRAME_DESC_ENTRY_MAX to 8 Tomi Valkeinen
2021-04-18 19:06   ` Laurent Pinchart
2021-04-16  8:38 ` [PATCH v5 00/24] v4l: subdev internal routing Niklas Söderlund
2021-04-16  8:47   ` Tomi Valkeinen
2021-04-16  8:56     ` Niklas Söderlund
2021-04-18 17:32 ` Laurent Pinchart
2021-04-21 12:57   ` Tomi Valkeinen
2021-04-29  1:27     ` Laurent Pinchart

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