Re: [PATCH] media: rockchip: rga: don't change RGB quantization

[Nicolas Dufresne <nicolas.dufresne@collabora.com>]

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Le vendredi 05 juin 2026 à 15:32 +0200, Sven Püschel a écrit :
> Don't change the quantization of an RGB format when converting between
> RGB and YUV with the RGA3. As the RGA3 only supports doing conversions
> to full range YUV with BT601, it wants to announce it through
> try_fmt/s_fmt.
> 
> As it is only relevant, when converting between RGB and YUV, it's
> guarded by a given condition. But the condition also causes the
> RGB format quantization to be adjusted to limited range, which
> is incorrect.
> 
> Therefore simplify the condition to only apply when the current format
> is a YUV format. Also document the reason for checking if the other
> format is an RGB format.
> 
> Fixes: 24a63d4c9d3c ("media: rockchip: rga: add rga3 support")
> Signed-off-by: Sven Püschel <s.pueschel@pengutronix.de>

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

> ---
> This patch is a fix to the upcoming RGA3 support. By mistake it'll also
> adjust the RGB quantization instead of only adjusting the quantization
> of the YUV formats. Therefore remove the incorrect conditions and
> document why we also check the format of the other side.
> 
> I've just noticed this flawed condition and didn't check/reproduce it in
> a practical scenario.
> 
>     v4l2-compliance 1.32.0, 64 bits, 64-bit time_t
>     ....
>     	Card type        : rga3
>     ...
>     Total for rockchip-rga device /dev/video0: 48, Succeeded: 48, Failed: 0, Warnings: 0
> 
>     v4l2-compliance 1.32.0, 64 bits, 64-bit time_t
>     ...
>     	Card type        : rga2
>     ...
>     Total for rockchip-rga device /dev/video1: 48, Succeeded: 48, Failed: 0, Warnings: 0
> ---
>  drivers/media/platform/rockchip/rga/rga3-hw.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rga/rga3-hw.c b/drivers/media/platform/rockchip/rga/rga3-hw.c
> index ca1c268303dd4..c4a71306278ba 100644
> --- a/drivers/media/platform/rockchip/rga/rga3-hw.c
> +++ b/drivers/media/platform/rockchip/rga/rga3-hw.c
> @@ -450,10 +450,14 @@ static void *rga3_adjust_and_map_format(struct rga_ctx *ctx,
>  	other_format = is_output ? &ctx->out.pix : &ctx->in.pix;
>  	other_format_info = v4l2_format_info(other_format->pixelformat);
>  
> -	if ((v4l2_is_format_rgb(format_info) &&
> -	     v4l2_is_format_yuv(other_format_info)) ||
> -	    (v4l2_is_format_yuv(format_info) &&
> -	     v4l2_is_format_rgb(other_format_info))) {
> +	/*
> +	 * Only apply the quantization restrictions when we need to
> +	 * convert between RGB and YUV. Otherwise there is no point
> +	 * to limit the quantization for operations like scaling or
> +	 * rotations.
> +	 */
> +	if (v4l2_is_format_yuv(format_info) &&
> +	    v4l2_is_format_rgb(other_format_info)) {
>  		/*
>  		 * The RGA3 only supports BT601, BT709 and BT2020 RGB<->YUV conversions
>  		 * Additionally BT709 and BT2020 only support limited range YUV.
> 
> ---
> base-commit: 6a75e3d4f6428b90f398354212e3a2e0172851d6
> change-id: 20260605-spu-fixrga3quantization-061c761a1d80
> 
> Best regards,
> --  
> Sven Püschel <s.pueschel@pengutronix.de>
> 

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