Hi Sakari,
On Tuesday 17 January 2012 21:21:39 Sakari Ailus wrote:
> On Mon, Jan 16, 2012 at 03:44:08PM +0100, Laurent Pinchart wrote:
> > On Wednesday 11 January 2012 22:26:54 Sakari Ailus wrote:
> > > v4l2_subdev_link_validate() is the default op for validating a link. In
> > > V4L2 subdev context, it is used to call a pad op which performs the
> > > proper link check without much extra work.
> > >
> > > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
> > > ---
> > >
> > > drivers/media/video/v4l2-subdev.c | 62
> > >
> > > +++++++++++++++++++++++++++++++++++++ include/media/v4l2-subdev.h
> > > |
> > >
> > > 10 ++++++
> > > 2 files changed, 72 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/drivers/media/video/v4l2-subdev.c
> > > b/drivers/media/video/v4l2-subdev.c index 836270d..4b329a0 100644
> > > --- a/drivers/media/video/v4l2-subdev.c
> > > +++ b/drivers/media/video/v4l2-subdev.c
> > > @@ -367,6 +367,68 @@ const struct v4l2_file_operations v4l2_subdev_fops
> > > = {
> > >
> > > .poll = subdev_poll,
> > >
> > > };
> > >
> > > +#ifdef CONFIG_MEDIA_CONTROLLER
> > > +int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd,
> > > + struct media_link *link,
> > > + struct v4l2_subdev_format *source_fmt,
> > > + struct v4l2_subdev_format *sink_fmt)
> > > +{
> > > + if (source_fmt->format.width != sink_fmt->format.width
> > > + || source_fmt->format.height != sink_fmt->format.height
> > > + || source_fmt->format.code != sink_fmt->format.code)
> > > + return -EINVAL;
> > > +
> > > + return 0;
> > > +}
> > > +EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate_default);
> >
> > What about calling this function directly from
> > v4l2_subdev_link_validate() if the pad::link_validate operation is NULL
> > ? That wouldn't require changing all subdev drivers to explicitly use
> > the default implementation.
>
> I can do that. I still want to keep the function available for those that
> want to call it explicitly to perform the above check.
>
> > > +
> > > +static struct v4l2_subdev_format
> > > +*v4l2_subdev_link_validate_get_format(struct media_pad *pad,
> > > + struct v4l2_subdev_format *fmt)
> > > +{
> > > + int rval;
> > > +
> > > + switch (media_entity_type(pad->entity)) {
> > > + case MEDIA_ENT_T_V4L2_SUBDEV:
> > > + fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > + fmt->pad = pad->index;
> > > + rval = v4l2_subdev_call(media_entity_to_v4l2_subdev(
> > > + pad->entity),
> > > + pad, get_fmt, NULL, fmt);
> > > + if (rval < 0)
> > > + return NULL;
> > > + return fmt;
> > > + case MEDIA_ENT_T_DEVNODE_V4L:
> > > + return NULL;
> > > + default:
> > > + BUG();
> >
> > Maybe WARN() and return NULL ?
>
> It's a clear driver BUG() if this happens. If you think the correct
> response to that is WARN() and return NULL, I can do that.
You're right.
> > > + }
> > > +}
> > > +
> > > +int v4l2_subdev_link_validate(struct media_link *link)
> > > +{
> > > + struct v4l2_subdev *sink = NULL, *source = NULL;
> > > + struct v4l2_subdev_format _sink_fmt, _source_fmt;
> > > + struct v4l2_subdev_format *sink_fmt, *source_fmt;
> > > +
> > > + source_fmt = v4l2_subdev_link_validate_get_format(
> > > + link->source, &_source_fmt);
> > > + sink_fmt = v4l2_subdev_link_validate_get_format(
> > > + link->sink, &_sink_fmt);
> > > +
> > > + if (source_fmt)
> > > + source = media_entity_to_v4l2_subdev(link->source->entity);
> > > + if (sink_fmt)
> > > + sink = media_entity_to_v4l2_subdev(link->sink->entity);
> > > +
> > > + if (source_fmt && sink_fmt)
> > > + return v4l2_subdev_call(sink, pad, link_validate, link,
> > > + source_fmt, sink_fmt);
> >
> > This looks overly complex. Why don't you return 0 if one of the two
> > entities is of a type different than MEDIA_ENT_T_V4L2_SUBDEV, then
> > retrieve the formats for the two entities and return 0 if one of the two
> > operation fails, and finally call pad::link_validate ?
>
> Now that you mention that, I agree. :-) I'll fix it.
--
Regards,
Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
