Linux-Media Archive on lore.kernel.org
 help / color / Atom feed
From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
	linux-media@vger.kernel.org,
	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 12/24] media: entity: Add an iterator helper for connected pads
Date: Tue, 20 Apr 2021 14:48:25 +0300
Message-ID: <20210420114825.GN3@paasikivi.fi.intel.com> (raw)
In-Reply-To: <YHx4U8F/g8dTusc+@pendragon.ideasonboard.com>

Hi Laurent,

Thanks for the review.

On Sun, Apr 18, 2021 at 09:20:03PM +0300, Laurent Pinchart wrote:
> Hi Tomi and Sakari,
> 
> Thank you for the patch.
> 
> On Thu, Apr 15, 2021 at 04:04:38PM +0300, Tomi Valkeinen wrote:
> > From: Sakari Ailus <sakari.ailus@linux.intel.com>
> > 
> > Add a helper macro for iterating over pads that are connected through
> > enabled routes. This can be used to find all the connected pads within an
> > entity, for instance starting from the pad which has been obtained during
> > the graph walk.
> > 
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > 
> > - Make __media_entity_next_routed_pad() return NULL and adjust the
> >   iterator to handle that
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  include/media/media-entity.h | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> > 
> > diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> > index 73de1c335e4e..edd6f60ed6b4 100644
> > --- a/include/media/media-entity.h
> > +++ b/include/media/media-entity.h
> > @@ -916,6 +916,33 @@ __must_check int media_graph_walk_init(
> >  bool media_entity_has_route(struct media_entity *entity, unsigned int pad0,
> >  			    unsigned int pad1);
> >  
> > +static inline struct media_pad *__media_entity_next_routed_pad(
> > +	struct media_pad *start, struct media_pad *iter)
> > +{
> > +	struct media_entity *entity = start->entity;
> > +
> > +	for (; iter < &entity->pads[entity->num_pads]; iter++)
> > +		if (media_entity_has_route(entity, start->index, iter->index))
> > +			return iter;
> 
> I'd use curly braces.
> 
> > +
> > +	return NULL;
> > +}
> 
> Does this need to be inlined ?

I guess it doesn't have to. It's used inside loops and it's rather small so
I think it should be fine that way.

> 
> > +
> > +/**
> > + * media_entity_for_each_routed_pad - Iterate over entity pads connected by routes
> 
> "routed" sounds a bit weird. Would media_entity_for_each_connected_pad()
> be a better name ?

"Connected" is often used in context of links. We're dealing with routes
here, so I thought "routed" is appropriate to avoid confusion.

> 
> > + *
> > + * @start: The stating pad
> 
> s/stating/starting/
> 
> > + * @iter: The iterator pad
> > + *
> > + * Iterate over all pads connected through routes from a given pad
> 
> "from the @start pad"
> 
> > + * within an entity. The iteration will include the starting pad itself.
> 
> s/starting/@start/
> 
> I wonder if it wouldn't be more logical to not include the start pad.
> That wouldn't match the current usage patterns, which would need to be
> adapted accordingly, but I'm worried that including the start pad will
> lead to annoying bugs in the future. Maybe I worry too much.

The aim here is to find all pads that are routed to another pad within the
same entity. If you remove the start pad, it becomes a task harder than
difficult.

> 
> And now that I reread the patch, I also wonder if "start" is a good
> name, as it implies we start the enumeration from a given pad, while we
> enumerate all pads connected to a given pad. I'm not sure what a better
> name would be though, maybe just pad ?

There are two pads here. Therefore explicitly calling them something else
makes sense IMO.

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

I agree on the comments I didn't reply to.

Thank you!

> 
> > + */
> > +#define media_entity_for_each_routed_pad(start, iter)			\
> > +	for (iter = __media_entity_next_routed_pad(			\
> > +		     start, (start)->entity->pads);			\
> > +	     iter != NULL;						\
> > +	     iter = __media_entity_next_routed_pad(start, iter + 1))
> > +
> >  /**
> >   * media_graph_walk_cleanup - Release resources used by graph walk.
> >   *
> 

-- 
Kind regards,

Sakari Ailus

  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 [this message]
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
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210420114825.GN3@paasikivi.fi.intel.com \
    --to=sakari.ailus@linux.intel.com \
    --cc=hverkuil-cisco@xs4all.nl \
    --cc=jacopo+renesas@jmondi.org \
    --cc=laurent.pinchart@ideasonboard.com \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab@kernel.org \
    --cc=niklas.soderlund+renesas@ragnatech.se \
    --cc=tomi.valkeinen@ideasonboard.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Media Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-media/0 linux-media/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-media linux-media/ https://lore.kernel.org/linux-media \
		linux-media@vger.kernel.org
	public-inbox-index linux-media

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-media


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git