Hi Laurent,
Thanks for the review!
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.
> > + }
> > +}
> > +
> > +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,
--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx jabber/XMPP/Gmail: sailus@xxxxxxxxxxxxxx
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