This is a note to let you know that I've just added the patch titled
drm/mediatek: Fix YCbCr422 color format issue for DP
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-ycbcr422-color-format-issue-for-dp.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 f6fe998e794f95f17995bd2414aaa5fe42addd70
Author: Liankun Yang <liankun.yang@xxxxxxxxxxxx>
Date: Fri Oct 25 16:28:27 2024 +0800
drm/mediatek: Fix YCbCr422 color format issue for DP
[ Upstream commit ef24fbd8f12015ff827973fffefed3902ffd61cc ]
Setting up misc0 for Pixel Encoding Format.
According to the definition of YCbCr in spec 1.2a Table 2-96,
0x1 << 1 should be written to the register.
Use switch case to distinguish RGB, YCbCr422,
and unsupported color formats.
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang <liankun.yang@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241025083036.8829-2-liankun.yang@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_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 48a4defbc66c..399423cb618c 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -458,18 +458,16 @@ static int mtk_dp_set_color_format(struct mtk_dp *mtk_dp,
enum dp_pixelformat color_format)
{
u32 val;
-
- /* update MISC0 */
- mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3034,
- color_format << DP_TEST_COLOR_FORMAT_SHIFT,
- DP_TEST_COLOR_FORMAT_MASK);
+ u32 misc0_color;
switch (color_format) {
case DP_PIXELFORMAT_YUV422:
val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_YCBCR422;
+ misc0_color = DP_COLOR_FORMAT_YCbCr422;
break;
case DP_PIXELFORMAT_RGB:
val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_RGB;
+ misc0_color = DP_COLOR_FORMAT_RGB;
break;
default:
drm_warn(mtk_dp->drm_dev, "Unsupported color format: %d\n",
@@ -477,6 +475,11 @@ static int mtk_dp_set_color_format(struct mtk_dp *mtk_dp,
return -EINVAL;
}
+ /* update MISC0 */
+ mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3034,
+ misc0_color,
+ DP_TEST_COLOR_FORMAT_MASK);
+
mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_303C,
val, PIXEL_ENCODE_FORMAT_DP_ENC0_P0_MASK);
return 0;
