[PATCH v9 14/21] drm/mediatek: Support "None" blending in OVL

[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 at mediatek.com>
> 
> Support "None" alpha blending mode on MediaTek's chips.

Reviewed-by: CK Hu <ck.hu at mediatek.com>

> 
> Signed-off-by: Hsiao Chien Sung <shawn.sung at mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index 2316d4a6dca7..6567806cf4e2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -431,6 +431,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
>  	unsigned int fmt = pending->format;
>  	unsigned int offset = (pending->y << 16) | pending->x;
>  	unsigned int src_size = (pending->height << 16) | pending->width;
> +	unsigned int blend_mode = state->base.pixel_blend_mode;
>  	unsigned int ignore_pixel_alpha = 0;
>  	unsigned int con;
>  	bool is_afbc = pending->modifier != DRM_FORMAT_MOD_LINEAR;
> @@ -460,7 +461,8 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
>  	 * For RGB888 related formats, whether CONST_BLD is enabled or not won't
>  	 * affect the result. Therefore we use !has_alpha as the condition.
>  	 */
> -	if (state->base.fb && !state->base.fb->format->has_alpha)
> +	if ((state->base.fb && !state->base.fb->format->has_alpha) ||
> +	    blend_mode == DRM_MODE_BLEND_PIXEL_NONE)
>  		ignore_pixel_alpha = OVL_CONST_BLEND;
>  
>  	if (pending->rotation & DRM_MODE_REFLECT_Y) {