Re: [PATCH v6 1/9] media: mc-entity: Store parsed V4L2 fwnode endpoint in media_pad

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

On Sun, Jun 28, 2026 at 11:28:13PM +0300, Sakari Ailus wrote:
> On Wed, Jun 24, 2026 at 04:37:48PM -0400, Frank.Li@oss.nxp.com wrote:
> > From: Frank Li <Frank.Li@nxp.com>
> > 
> > Each media pad is associated with a firmware node endpoint. Capture the
> > parsed V4L2 fwnode endpoint information in struct media_pad so it can be
> > reused by consumers.
> > 
> > This avoids reparsing firmware node endpoint data every time the endpoint
> > configuration is needed, reduces duplicate code, and provides a common
> > place to store endpoint properties associated with a pad.
> > 
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > Assume 1 to 1 map between dt's endpoint to medie pad.
> > Change in v6
> > - new patch
> > ---
> >  include/media/media-entity.h | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> > index d9b72cd87d524..4a3785cd9f370 100644
> > --- a/include/media/media-entity.h
> > +++ b/include/media/media-entity.h
> > @@ -20,6 +20,8 @@
> >  #include <linux/minmax.h>
> >  #include <linux/types.h>
> >  
> > +#include <media/v4l2-fwnode.h>
> 
> We have dependencies from V4L2 to MC but not the other way around as MC is
> (or was?) intended for wider use then just V4L2. I'm thus more than a bit
> hesitant adding any references to V4L2 in MC.
> 
> I wonder what Hans and Laurent think.

I agree. Furthermore, this will significantly increase the size of the
media_pad structure, for all pads. That's not a good design.

> > +
> >  /* Enums used internally at the media controller to represent graphs */
> >  
> >  /**
> > @@ -230,6 +232,7 @@ enum media_pad_signal_type {
> >   * @flags:	Pad flags, as defined in
> >   *		:ref:`include/uapi/linux/media.h <media_header>`
> >   *		(seek for ``MEDIA_PAD_FL_*``)
> > + * @vep:	associated fwnode endpoint information
> >   * @pipe:	Pipeline this pad belongs to. Use media_entity_pipeline() to
> >   *		access this field.
> >   */
> > @@ -240,7 +243,7 @@ struct media_pad {
> >  	u16 num_links;
> >  	enum media_pad_signal_type sig_type;
> >  	unsigned long flags;
> > -
> > +	struct v4l2_fwnode_endpoint vep;
> >  	/*
> >  	 * The fields below are private, and should only be accessed via
> >  	 * appropriate functions.
> > 
> 
> -- 
> Regards,
> 
> Sakari Ailus

-- 
Regards,

Laurent Pinchart