Re: [PATCH v3 28/29] media: v4l2-subdev: Use v4l2_subdev_get_frame_desc() for passthrough

On Mon, Aug 24, 2026 at 03:14:50PM +0300, Sakari Ailus wrote:
> Call v4l2_subdev_get_frame_desc() to obtain the frame descriptor in
> __v4l2_subdev_get_frame_desc_passthrough(). This is preferred over calling
> the get_frame_desc() pad operation directly.
>
> Signed-off-by: Sakari Ailus <[email protected]>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 34 +++++++++++++--------------
>  1 file changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 8c3c5b6e4ee8..2172bb8313ec 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -2558,6 +2558,7 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
>  					     unsigned int pad,
>  					     struct v4l2_mbus_frame_desc *fd)
>  {
> +	struct v4l2_mbus_frame_desc *source_fd = NULL;

why not use auto cleanup like other patches? look like only use in loop
media_entity_for_each_pad()

Frank
>  	struct media_pad *local_sink_pad;
>  	struct v4l2_subdev_route *route;
>  	struct device *dev = sd->dev;
> @@ -2599,9 +2600,6 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
>
>  	/* Iterate over sink pads */
>  	media_entity_for_each_pad(&sd->entity, local_sink_pad) {
> -		struct v4l2_mbus_frame_desc source_fd;
> -		bool have_source_fd = false;
> -
>  		if (!(local_sink_pad->flags & MEDIA_PAD_FL_SINK))
>  			continue;
>
> @@ -2618,7 +2616,7 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
>  			    route->sink_pad != local_sink_pad->index)
>  				continue;
>
> -			if (!have_source_fd) {
> +			if (!source_fd) {
>  				remote_source_pad = media_pad_remote_pad_unique(local_sink_pad);
>  				if (IS_ERR(remote_source_pad)) {
>  					dev_dbg(dev, "Failed to find remote pad for sink pad %u\n",
> @@ -2633,33 +2631,31 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
>  					goto err_free;
>  				}
>
> -				ret = v4l2_subdev_call(remote_sd, pad,
> -						       get_frame_desc,
> -						       remote_source_pad->index,
> -						       &source_fd);
> -				if (ret) {
> +				source_fd = v4l2_subdev_get_frame_desc(remote_sd,
> +								       remote_source_pad->index,
> +								       fd->type);
> +				if (IS_ERR(source_fd)) {
> +					ret = PTR_ERR(source_fd);
>  					dev_err(dev,
>  						"Failed to get frame desc from remote subdev %s\n",
>  						remote_sd->name);
>  					goto err_free;
>  				}
>
> -				have_source_fd = true;
> -
>  				if (fd->num_entries == 0) {
> -					fd->type = source_fd.type;
> -				} else if (fd->type != source_fd.type) {
> +					fd->type = source_fd->type;
> +				} else if (fd->type != source_fd->type) {
>  					dev_err(dev,
>  						"Frame desc type mismatch: %u != %u\n",
> -						fd->type, source_fd.type);
> +						fd->type, source_fd->type);
>  					ret = -EPIPE;
>  					goto err_free;
>  				}
>  			}
>
> -			for (unsigned int i = 0; i < source_fd.num_entries; i++) {
> -				if (source_fd.entry[i].stream == route->sink_stream) {
> -					source_entry = &source_fd.entry[i];
> +			for (unsigned int i = 0; i < source_fd->num_entries; i++) {
> +				if (source_fd->entry[i].stream == route->sink_stream) {
> +					source_entry = &source_fd->entry[i];
>  					break;
>  				}
>  			}
> @@ -2684,11 +2680,15 @@ int __v4l2_subdev_get_frame_desc_passthrough(struct v4l2_subdev *sd,
>
>  			fd->num_entries++;
>  		}
> +
> +		v4l2_subdev_free_frame_desc(source_fd);
> +		source_fd = NULL;
>  	}
>
>  	return 0;
>
>  err_free:
> +	v4l2_subdev_free_frame_desc(source_fd);
>  	kfree(fd->entry);
>  	fd->entry = fd->entry_mem;
>  	fd->num_entries = 0;
> --
> 2.47.3
>