Re: [PATCH 1/3] media: uvcvideo: Drop unneeded memset() in meta device ioctl handlers

[Ricardo Ribalda <ribalda@chromium.org>]

On Tue, 15 Jul 2025 at 20:53, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> The .vidioc_g_fmt_meta_cap() and .vidioc_enum_fmt_meta_cap() ioctl
> handlers for meta capture devices memset the ioctl argument structure to
> zero. This is unnecessary as the memory is already zeroed by the V4L2
> ioctl core. Drop the memset(), which, in uvc_meta_v4l2_enum_formats(),
> also allows further simplification as structure fields don't need to be
> saved and restored.
>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/usb/uvc/uvc_metadata.c | 11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
> index 229e08ff323e..b68bfb2d47df 100644
> --- a/drivers/media/usb/uvc/uvc_metadata.c
> +++ b/drivers/media/usb/uvc/uvc_metadata.c
> @@ -49,8 +49,6 @@ static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
>         if (format->type != vfh->vdev->queue->type)
>                 return -EINVAL;
>
> -       memset(fmt, 0, sizeof(*fmt));
> -
>         fmt->dataformat = stream->meta.format;
>         fmt->buffersize = UVC_METADATA_BUF_SIZE;
>
> @@ -118,19 +116,14 @@ static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
>         struct v4l2_fh *vfh = file->private_data;
>         struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
>         struct uvc_device *dev = stream->dev;
> -       u32 i = fdesc->index;
>
>         if (fdesc->type != vfh->vdev->queue->type)
>                 return -EINVAL;
>
> -       if (i >= dev->nmeta_formats)
> +       if (fdesc->index >= dev->nmeta_formats)
>                 return -EINVAL;
>
> -       memset(fdesc, 0, sizeof(*fdesc));
> -
> -       fdesc->type = vfh->vdev->queue->type;
> -       fdesc->index = i;
> -       fdesc->pixelformat = dev->meta_formats[i];
> +       fdesc->pixelformat = dev->meta_formats[fdesc->index];
>
>         return 0;
>  }
> --
> Regards,
>
> Laurent Pinchart
>


-- 
Ricardo Ribalda