Hi Sakari,
Thanks for the patch.
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.
> +
> +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 ?
> + }
> +}
> +
> +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 ?
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate);
> +#endif /* CONFIG_MEDIA_CONTROLLER */
> +
> void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops
> *ops) {
> INIT_LIST_HEAD(&sd->list);
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index feab950..436e6f4 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -470,6 +470,11 @@ struct v4l2_subdev_pad_ops {
> struct v4l2_subdev_selection *sel);
> int (*set_selection)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
> struct v4l2_subdev_selection *sel);
> +#ifdef CONFIG_MEDIA_CONTROLLER
> + int (*link_validate)(struct v4l2_subdev *sd, struct media_link *link,
> + struct v4l2_subdev_format *source_fmt,
> + struct v4l2_subdev_format *sink_fmt);
> +#endif /* CONFIG_MEDIA_CONTROLLER */
> };
>
> struct v4l2_subdev_ops {
> @@ -606,6 +611,11 @@ static inline void *v4l2_get_subdev_hostdata(const
> struct v4l2_subdev *sd) return sd->host_priv;
> }
>
> +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);
> +int v4l2_subdev_link_validate(struct media_link *link);
> void v4l2_subdev_init(struct v4l2_subdev *sd,
> const struct v4l2_subdev_ops *ops);
--
Regards,
Laurent Pinchart
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