Commit 995d4d55 authored by Jason-JH.Lin's avatar Jason-JH.Lin Committed by Chun-Kuang Hu
Browse files

drm/mediatek: ovl: Fix XRGB format breakage for blend_modes unsupported SoCs 



OVL_CON_AEN is for alpha blending enable.
For the SoC that is supported the blend_modes, OVL_CON_AEN will always
enabled to use constant alpha and then use the ignore_pixel_alpha bit
to do the alpha blending for XRGB8888 format.
Note that ignore pixel alpha bit is not supported if the SoC is not
supported the blend_modes.
So it will break the original setting of XRGB8888 format for the
blend_modes unsupported SoCs, such as MT8173.

To fix the downgrade issue, enable alpha blending only when a valid
blend_mode or has_alpha is set.

Fixes: bc46eb5d ("drm/mediatek: Support DRM plane alpha in OVL")
Signed-off-by: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241009034646.13143-2-jason-jh.lin@mediatek.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 9852d85e

drivers/gpu/drm/mediatek/mtk_disp_ovl.c

+7 −1
Original line number Diff line number Diff line
@@ -473,8 +473,14 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx, 


	con = ovl_fmt_convert(ovl, fmt, blend_mode);

	if (state->base.fb) {

		con |= OVL_CON_AEN;

		con |= state->base.alpha & OVL_CON_ALPHA;



		/*

		 * For blend_modes supported SoCs, always enable alpha blending.

		 * For blend_modes unsupported SoCs, enable alpha blending when has_alpha is set.

		 */

		if (blend_mode || state->base.fb->format->has_alpha)

			con |= OVL_CON_AEN;

	}



	/* CONST_BLD must be enabled for XRGB formats although the alpha channel