[PATCH for 5.3] videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use

[PATCH for 5.3] videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use

[Hans Verkuil]

The V4L2_PIX_FMT_BGRA444 define clashed with the pre-existing V4L2_PIX_FMT_SGRBG12
which strangely enough used the same fourcc, even though that fourcc made no sense
for a Bayer format. In any case, you can't have duplicates, so change the fourcc of
V4L2_PIX_FMT_BGRA444.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org>      # for v5.2 and up
---
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 9d9705ceda76..2427bc4d8eba 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -518,7 +518,13 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_RGBX444 v4l2_fourcc('R', 'X', '1', '2') /* 16  rrrrgggg bbbbxxxx */
 #define V4L2_PIX_FMT_ABGR444 v4l2_fourcc('A', 'B', '1', '2') /* 16  aaaabbbb ggggrrrr */
 #define V4L2_PIX_FMT_XBGR444 v4l2_fourcc('X', 'B', '1', '2') /* 16  xxxxbbbb ggggrrrr */
-#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('B', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
+
+/*
+ * Originally this had 'BA12' as fourcc, but this clashed with the older
+ * V4L2_PIX_FMT_SGRBG12 which inexplicably used that same fourcc.
+ * So use 'GA12' instead for V4L2_PIX_FMT_BGRA444.
+ */
+#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('G', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
 #define V4L2_PIX_FMT_BGRX444 v4l2_fourcc('B', 'X', '1', '2') /* 16  bbbbgggg rrrrxxxx */
 #define V4L2_PIX_FMT_RGB555  v4l2_fourcc('R', 'G', 'B', 'O') /* 16  RGB-5-5-5     */
 #define V4L2_PIX_FMT_ARGB555 v4l2_fourcc('A', 'R', '1', '5') /* 16  ARGB-1-5-5-5  */

Re: [PATCH for 5.3] videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use

[Laurent Pinchart]

Hi Hans,

Thank you for the patch.

On Thu, Jul 11, 2019 at 10:53:25AM +0200, Hans Verkuil wrote:
> The V4L2_PIX_FMT_BGRA444 define clashed with the pre-existing V4L2_PIX_FMT_SGRBG12
> which strangely enough used the same fourcc, even though that fourcc made no sense
> for a Bayer format. In any case, you can't have duplicates, so change the fourcc of
> V4L2_PIX_FMT_BGRA444.
> 
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Cc: <stable@vger.kernel.org>      # for v5.2 and up

Maybe a Fixes: line ?

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 9d9705ceda76..2427bc4d8eba 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -518,7 +518,13 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_RGBX444 v4l2_fourcc('R', 'X', '1', '2') /* 16  rrrrgggg bbbbxxxx */
>  #define V4L2_PIX_FMT_ABGR444 v4l2_fourcc('A', 'B', '1', '2') /* 16  aaaabbbb ggggrrrr */
>  #define V4L2_PIX_FMT_XBGR444 v4l2_fourcc('X', 'B', '1', '2') /* 16  xxxxbbbb ggggrrrr */
> -#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('B', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
> +
> +/*
> + * Originally this had 'BA12' as fourcc, but this clashed with the older
> + * V4L2_PIX_FMT_SGRBG12 which inexplicably used that same fourcc.
> + * So use 'GA12' instead for V4L2_PIX_FMT_BGRA444.
> + */
> +#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('G', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
>  #define V4L2_PIX_FMT_BGRX444 v4l2_fourcc('B', 'X', '1', '2') /* 16  bbbbgggg rrrrxxxx */
>  #define V4L2_PIX_FMT_RGB555  v4l2_fourcc('R', 'G', 'B', 'O') /* 16  RGB-5-5-5     */
>  #define V4L2_PIX_FMT_ARGB555 v4l2_fourcc('A', 'R', '1', '5') /* 16  ARGB-1-5-5-5  */

-- 
Regards,

Laurent Pinchart

Re: [PATCH for 5.3] videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use

[Kieran Bingham]

Hi Hans,

On 11/07/2019 09:53, Hans Verkuil wrote:
> The V4L2_PIX_FMT_BGRA444 define clashed with the pre-existing V4L2_PIX_FMT_SGRBG12
> which strangely enough used the same fourcc, even though that fourcc made no sense
> for a Bayer format. In any case, you can't have duplicates, so change the fourcc of
> V4L2_PIX_FMT_BGRA444.

Aha - I started looking at this this morning as well, and I see you've
beaten me to a patch.

That's a good thing anyway, as I was worried about what the actual code
should be instead, but hey I got to spend some time looking at how these
are all laid out.

There's not a lot of choice of letters left, with BA12 and RA12,
consumed, so GA12 seems reasonable.

It's a shame the SRGB formats didn't choose an 'S' leading char or such.

> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Cc: <stable@vger.kernel.org>      # for v5.2 and up

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>


> ---
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 9d9705ceda76..2427bc4d8eba 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -518,7 +518,13 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_RGBX444 v4l2_fourcc('R', 'X', '1', '2') /* 16  rrrrgggg bbbbxxxx */
>  #define V4L2_PIX_FMT_ABGR444 v4l2_fourcc('A', 'B', '1', '2') /* 16  aaaabbbb ggggrrrr */
>  #define V4L2_PIX_FMT_XBGR444 v4l2_fourcc('X', 'B', '1', '2') /* 16  xxxxbbbb ggggrrrr */
> -#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('B', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
> +
> +/*
> + * Originally this had 'BA12' as fourcc, but this clashed with the older
> + * V4L2_PIX_FMT_SGRBG12 which inexplicably used that same fourcc.
> + * So use 'GA12' instead for V4L2_PIX_FMT_BGRA444.
> + */
> +#define V4L2_PIX_FMT_BGRA444 v4l2_fourcc('G', 'A', '1', '2') /* 16  bbbbgggg rrrraaaa */
>  #define V4L2_PIX_FMT_BGRX444 v4l2_fourcc('B', 'X', '1', '2') /* 16  bbbbgggg rrrrxxxx */
>  #define V4L2_PIX_FMT_RGB555  v4l2_fourcc('R', 'G', 'B', 'O') /* 16  RGB-5-5-5     */
>  #define V4L2_PIX_FMT_ARGB555 v4l2_fourcc('A', 'R', '1', '5') /* 16  ARGB-1-5-5-5  */
>