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

[Shawn Sung]

From: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>

Support "None" alpha blending mode on MediaTek's chips.

Signed-off-by: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
---
 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) {
-- 
2.18.0