Patch "drm/mediatek: Fix XRGB setting error in Mixer" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/mediatek: Fix XRGB setting error in Mixer

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-mediatek-fix-xrgb-setting-error-in-mixer.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a326be785ca2cb24c12ad5833f8faa60d3feaa1d
Author: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
Date:   Thu Jun 20 00:38:44 2024 +0800

    drm/mediatek: Fix XRGB setting error in Mixer
    
    [ Upstream commit 8e418bee401b7cfd0bc40d187afea2c6b08b44ec ]
    
    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.
    
    Fixes: d886c0009bd0 ("drm/mediatek: Add ETHDR support for MT8195")
    Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
    Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
    Signed-off-by: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
    Link: https://patchwork.kernel.org/project/dri-devel/patch/20240620-igt-v3-4-a9d62d2e2c7e@xxxxxxxxxxxx/
    Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/mediatek/mtk_ethdr.c b/drivers/gpu/drm/mediatek/mtk_ethdr.c
index 5b5a0e149e0a3..5a740d85bea65 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);
 
@@ -167,7 +168,15 @@ 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,
+	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);