On 05/10/2021 10:57, Tomi Valkeinen wrote:
> Update v4l2_subdev_link_validate() to use routing and streams for
> validation.
>
> Instead of just looking at the format on the pad on both ends of the
> link, the routing tables are used to collect all the streams going from
> the source to the sink over the link, and the streams' formats on both
> ends of the link are verified.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-subdev.c | 217 +++++++++++++++++++++++---
> 1 file changed, 199 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index f63826755057..37e2e1f907fc 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -16,6 +16,7 @@
> #include <linux/videodev2.h>
> #include <linux/export.h>
> #include <linux/version.h>
> +#include <linux/sort.h>
>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> @@ -1050,6 +1051,7 @@ EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate_default);
>
> static int
> v4l2_subdev_link_validate_get_format(struct media_pad *pad,
> + u32 stream,
> struct v4l2_subdev_format *fmt)
> {
> if (is_media_entity_v4l2_subdev(pad->entity)) {
> @@ -1061,6 +1063,7 @@ v4l2_subdev_link_validate_get_format(struct media_pad *pad,
>
> fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
> fmt->pad = pad->index;
> + fmt->stream = stream;
> return v4l2_subdev_call(sd, pad, get_fmt, state, fmt);
> }
>
> @@ -1071,31 +1074,209 @@ v4l2_subdev_link_validate_get_format(struct media_pad *pad,
> return -EINVAL;
> }
>
> -int v4l2_subdev_link_validate(struct media_link *link)
> +static int cmp_u32(const void *a, const void *b)
> {
> - struct v4l2_subdev *sink;
> - struct v4l2_subdev_format sink_fmt, source_fmt;
> - int rval;
> + u32 a32 = *(u32 *)a;
> + u32 b32 = *(u32 *)b;
>
> - rval = v4l2_subdev_link_validate_get_format(
> - link->source, &source_fmt);
> - if (rval < 0)
> - return 0;
> + return a32 > b32 ? 1 : (a32 < b32 ? -1 : 0);
> +}
> +
> +static int v4l2_link_validate_get_streams(struct media_link *link,
> + bool is_source, u32 *out_num_streams,
> + const u32 **out_streams,
> + bool *allocated)
> +{
> + static const u32 default_streams[] = { 0 };
Hmm, I'd just write 'static const u32 default_stream = 0;'
> + struct v4l2_subdev_krouting *routing;
> + struct v4l2_subdev *subdev;
> + u32 num_streams;
> + u32 *streams;
> + unsigned int i;
> + struct v4l2_subdev_state *state;
> +
> + if (is_source)
> + subdev = media_entity_to_v4l2_subdev(link->source->entity);
> + else
> + subdev = media_entity_to_v4l2_subdev(link->sink->entity);
>
> - rval = v4l2_subdev_link_validate_get_format(
> - link->sink, &sink_fmt);
> - if (rval < 0)
> + if (!(subdev->flags & V4L2_SUBDEV_FL_MULTIPLEXED)) {
> + *out_num_streams = 1;
> + *out_streams = default_streams;
and here write = &default_stream;
That feels more natural.
> + *allocated = false;
> return 0;
> + }
>
> - sink = media_entity_to_v4l2_subdev(link->sink->entity);
> + state = v4l2_subdev_lock_active_state(subdev);
>
> - rval = v4l2_subdev_call(sink, pad, link_validate, link,
> - &source_fmt, &sink_fmt);
> - if (rval != -ENOIOCTLCMD)
> - return rval;
> + routing = &state->routing;
> +
> + streams = kmalloc_array(routing->num_routes, sizeof(u32), GFP_KERNEL);
> +
> + if (!streams) {
> + v4l2_subdev_unlock_state(state);
> + return -ENOMEM;
> + }
> +
> + num_streams = 0;
> +
> + for (i = 0; i < routing->num_routes; ++i) {
> + struct v4l2_subdev_route *route = &routing->routes[i];
> + int j;
> + u32 route_pad;
> + u32 route_stream;
> + u32 link_pad;
> +
> + if (is_source) {
> + route_pad = route->source_pad;
> + route_stream = route->source_stream;
> + link_pad = link->source->index;
> + } else {
> + route_pad = route->sink_pad;
> + route_stream = route->sink_stream;
> + link_pad = link->sink->index;
> + }
> +
> + if (!(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
> + continue;
> +
> + if (route_pad != link_pad)
> + continue;
> +
> + /* look for duplicates... */
> + for (j = 0; j < num_streams; ++j) {
> + if (streams[j] == route_stream)
> + break;
> + }
> +
> + /* ...and drop the stream if we already have it */
> + if (j != num_streams)
> + continue;
> +
> + streams[num_streams++] = route_stream;
> + }
> +
> + v4l2_subdev_unlock_state(state);
> +
> + sort(streams, num_streams, sizeof(u32), &cmp_u32, NULL);
> +
> + *out_num_streams = num_streams;
> + *out_streams = streams;
> + *allocated = true;
>
> - return v4l2_subdev_link_validate_default(
> - sink, link, &source_fmt, &sink_fmt);
> + return 0;
> +}
> +
> +int v4l2_subdev_link_validate(struct media_link *link)
> +{
> + struct v4l2_subdev *sink_subdev =
> + media_entity_to_v4l2_subdev(link->sink->entity);
> + struct device *dev = sink_subdev->entity.graph_obj.mdev->dev;
> + u32 num_source_streams;
> + const u32 *source_streams;
> + bool source_allocated;
> + u32 num_sink_streams;
> + const u32 *sink_streams;
> + bool sink_allocated;
> + unsigned int sink_idx;
> + unsigned int source_idx;
> + int ret;
> +
> + dev_dbg(dev, "validating link \"%s\":%u -> \"%s\":%u\n",
> + link->source->entity->name, link->source->index,
> + link->sink->entity->name, link->sink->index);
> +
> + ret = v4l2_link_validate_get_streams(link, true, &num_source_streams,
> + &source_streams,
> + &source_allocated);
> + if (ret)
> + return ret;
> +
> + ret = v4l2_link_validate_get_streams(link, false, &num_sink_streams,
> + &sink_streams, &sink_allocated);
> + if (ret)
> + goto free_source;
> +
> + /* It is ok to have more source streams than sink streams */
Why? Because that means that those extra streams are just ignored on the sink side
of the link?
In any case, state the reason why it is ok.
> + if (num_source_streams < num_sink_streams) {
> + dev_err(dev,
> + "Not enough source streams: %d < %d\n",
> + num_source_streams, num_sink_streams);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + /* Validate source and sink stream formats */
> +
> + source_idx = 0;
> +
> + for (sink_idx = 0; sink_idx < num_sink_streams; ++sink_idx) {
> + struct v4l2_subdev_format sink_fmt, source_fmt;
> + u32 stream;
> +
> + stream = sink_streams[sink_idx];
> +
> + for (; source_idx < num_source_streams; ++source_idx) {
> + if (source_streams[source_idx] == stream)
> + break;
> + }
> +
> + if (source_idx == num_source_streams) {
> + dev_err(dev, "No source stream for sink stream %u\n",
> + stream);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + dev_dbg(dev, "validating stream \"%s\":%u:%u -> \"%s\":%u:%u\n",
> + link->source->entity->name, link->source->index, stream,
> + link->sink->entity->name, link->sink->index, stream);
> +
> + ret = v4l2_subdev_link_validate_get_format(link->source, stream,
> + &source_fmt);
> + if (ret < 0) {
> + dev_dbg(dev, "Failed to get format for \"%s\":%u:%u (but that's ok)\n",
> + link->source->entity->name, link->source->index,
> + stream);
> + ret = 0;
> + continue;
> + }
> +
> + ret = v4l2_subdev_link_validate_get_format(link->sink, stream,
> + &sink_fmt);
> + if (ret < 0) {
> + dev_dbg(dev, "Failed to get format for \"%s\":%u:%u (but that's ok)\n",
> + link->sink->entity->name, link->sink->index,
> + stream);
> + ret = 0;
> + continue;
> + }
> +
> + /* TODO: add stream number to link_validate() */
> + ret = v4l2_subdev_call(sink_subdev, pad, link_validate, link,
> + &source_fmt, &sink_fmt);
> + if (!ret)
> + continue;
> +
> + if (ret != -ENOIOCTLCMD)
> + goto out;
> +
> + ret = v4l2_subdev_link_validate_default(sink_subdev, link,
> + &source_fmt, &sink_fmt);
> +
> + if (ret)
> + goto out;
> + }
> +
> +out:
> + if (sink_allocated)
> + kfree(sink_streams);
> +
> +free_source:
> + if (source_allocated)
> + kfree(source_streams);
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate);
>
>
Regards,
Hans
