Re: [PATCH] v4l: doc: clarify v4l2_mbus_fmt height definition

From: Sakari Ailus
Date: Mon Jan 08 2018 - 10:14:00 EST


Hi Kieran,

On Mon, Jan 08, 2018 at 02:45:49PM +0000, Kieran Bingham wrote:
> The v4l2_mbus_fmt width and height corresponds directly with the
> v4l2_pix_format definitions, yet the differences in documentation make
> it ambiguous what to do in the event of field heights.
>
> Clarify this by referencing the v4l2_pix_format which is explicit on the
> matter, and by matching the terminology of 'image height' rather than
> the misleading 'frame height'.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> Documentation/media/uapi/v4l/subdev-formats.rst | 6 ++++--
> include/uapi/linux/v4l2-mediabus.h | 4 ++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/media/uapi/v4l/subdev-formats.rst b/Documentation/media/uapi/v4l/subdev-formats.rst
> index b1eea44550e1..a2a00202b430 100644
> --- a/Documentation/media/uapi/v4l/subdev-formats.rst
> +++ b/Documentation/media/uapi/v4l/subdev-formats.rst
> @@ -16,10 +16,12 @@ Media Bus Formats
>
> * - __u32
> - ``width``
> - - Image width, in pixels.
> + - Image width in pixels. See struct
> + :c:type:`v4l2_pix_format`.
> * - __u32
> - ``height``
> - - Image height, in pixels.
> + - Image height in pixels. See struct
> + :c:type:`v4l2_pix_format`.
> * - __u32
> - ``code``
> - Format code, from enum
> diff --git a/include/uapi/linux/v4l2-mediabus.h b/include/uapi/linux/v4l2-mediabus.h
> index 6e20de63ec59..6b34108d0338 100644
> --- a/include/uapi/linux/v4l2-mediabus.h
> +++ b/include/uapi/linux/v4l2-mediabus.h
> @@ -18,8 +18,8 @@
>
> /**
> * struct v4l2_mbus_framefmt - frame format on the media bus
> - * @width: frame width
> - * @height: frame height
> + * @width: image width
> + * @height: image height (see struct v4l2_pix_format)

Hmm. This is the media bus format and it has no direct relation to
v4l2_pix_format. So no, I can't see what would be the point in making such
a reference.

> * @code: data format code (from enum v4l2_mbus_pixelcode)
> * @field: used interlacing type (from enum v4l2_field)
> * @colorspace: colorspace of the data (from enum v4l2_colorspace)

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx