Re: [PATCH v3 15/29] media: v4l2-subdev: Return dynamically allocated pass-through routes

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Frank,

On Mon, Aug 24, 2026 at 05:00:16PM -0400, Frank Li wrote:
> On Mon, Aug 24, 2026 at 03:14:37PM +0300, Sakari Ailus wrote:
> > Count the number of pass-through routes, allocate memory and then return
> > the full table to the caller.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> >  drivers/media/v4l2-core/v4l2-subdev.c | 61 +++++++++++++++++++++++----
> >  1 file changed, 52 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> > index c9f38b0313eb..d34704aad88e 100644
> > --- a/drivers/media/v4l2-core/v4l2-subdev.c
> > +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> > @@ -2561,13 +2561,42 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
> >  	struct media_pad *local_sink_pad;
> >  	struct v4l2_subdev_route *route;
> >  	struct device *dev = sd->dev;
> > -	int ret = 0;
> > +	unsigned int num_entries = 0;
> > +	int ret;
> >
> >  	lockdep_assert_held(state->lock);
> >
> >  	if (WARN_ON(!(sd->entity.pads[pad].flags & MEDIA_PAD_FL_SOURCE)))
> >  		return -EINVAL;
> >
> > +	/* Count the number of entries first */
> > +	media_entity_for_each_pad(&sd->entity, local_sink_pad) {
> > +		if (!(local_sink_pad->flags & MEDIA_PAD_FL_SINK))
> > +			continue;
> > +
> > +		for_each_active_route(&state->routing, route) {
> > +			if (route->source_pad != pad ||
> > +			    route->sink_pad != local_sink_pad->index)
> > +				continue;
> > +
> > +			num_entries++;
> > +
> > +			if (num_entries > V4L2_FRAME_DESC_ENTRY_MAX)
> > +				return -E2BIG;
> > +		}
> > +	}
> > +
> > +	if (num_entries > V4L2_FRAME_DESC_ENTRY_MAX)
> > +		return -E2BIG;
> > +
> > +	if (num_entries > V4L2_FRAME_DESC_ENTRY_PREALLOC) {
> > +		fd->entry = kzalloc_objs(*fd->entry, num_entries, GFP_KERNEL);
> 
> nit: Default should be GFP_KERNEL, needn't GFP_KERNEL when call kzalloc_objs()

I'll drop that in v4.

> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>

Thank you.

-- 
Regards,

Sakari Ailus