Re: [PATCH v9 10/21] drm/mediatek: Fix XRGB setting error in Mixer

[CK Hu (胡俊光)]

Hi, Shawn:

On Fri, 2024-06-14 at 10:46 +0800, Shawn Sung wrote:
> From: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
> 
> Although the alpha channel in XRGB formats can be ignored, ALPHA_CON
> must be configured accordingly when using XRGB formats or it will still
> affects CRC generation.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> 
> Fixes: d886c0009bd0 ("drm/mediatek: Add ETHDR support for MT8195")
> Signed-off-by: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_ethdr.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_ethdr.c b/drivers/gpu/drm/mediatek/mtk_ethdr.c
> index 9796fd1d51f2..902dec03a7dd 100644
> --- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
> +++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
> @@ -153,6 +153,7 @@ void mtk_ethdr_layer_config(struct device *dev, unsigned int idx,
>  	unsigned int offset = (pending->x & 1) << 31 | pending->y << 16 | pending->x;
>  	unsigned int align_width = ALIGN_DOWN(pending->width, 2);
>  	unsigned int alpha_con = 0;
> +	bool replace_src_a = false;
>  
>  	dev_dbg(dev, "%s+ idx:%d", __func__, idx);
>  
> @@ -172,8 +173,15 @@ void mtk_ethdr_layer_config(struct device *dev, unsigned int idx,
>  	if (state->base.fb && state->base.fb->format->has_alpha)
>  		alpha_con = MIXER_ALPHA_AEN | MIXER_ALPHA;
>  
> -	mtk_mmsys_mixer_in_config(priv->mmsys_dev, idx + 1, alpha_con ? false : true,
> -				  MIXER_ALPHA,
> +	if (state->base.fb && !state->base.fb->format->has_alpha) {
> +		/*
> +		 * Mixer doesn't support CONST_BLD mode,
> +		 * use a trick to make the output equivalent
> +		 */
> +		replace_src_a = true;
> +	}
> +
> +	mtk_mmsys_mixer_in_config(priv->mmsys_dev, idx + 1, replace_src_a, MIXER_ALPHA,
>  				  pending->x & 1 ? MIXER_INX_MODE_EVEN_EXTEND :
>  				  MIXER_INX_MODE_BYPASS, align_width / 2 - 1, cmdq_pkt);
>