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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	Alexandre Mergnat <amergnat@baylibre.com>,
	CK Hu <ck.hu@mediatek.com>,
	Chun-Kuang Hu <chunkuang.hu@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.8 447/715] drm/mediatek: dsi: Fix DSI RGB666 formats and definitions
Date: Sun, 24 Mar 2024 18:30:26 -0400
Message-ID: <20240324223455.1342824-448-sashal@kernel.org>
In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org>
References: <20240324223455.1342824-1-sashal@kernel.org>
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From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

[ Upstream commit fae6f815505301b92d9113764f4d76d0bfe45607 ]

The register bits definitions for RGB666 formats are wrong in multiple
ways: first, in the DSI_PS_SEL bits region, the Packed 18-bits RGB666
format is selected with bit 1, while the Loosely Packed one is bit 2,
and second - the definition name "LOOSELY_PS_18BIT_RGB666" is wrong
because the loosely packed format is 24 bits instead!

Either way, functions mtk_dsi_ps_control_vact() and mtk_dsi_ps_control()
do not even agree on the DSI_PS_SEL bit to set in DSI_PSCTRL: one sets
loosely packed (24) on RGB666, the other sets packed (18), and the other
way around for RGB666_PACKED.

Fixing this entire stack of issues is done in one go:
 - Use the correct bit for the Loosely Packed RGB666 definition
 - Rename LOOSELY_PS_18BIT_RGB666 to LOOSELY_PS_24BIT_RGB666
 - Change ps_bpp_mode in mtk_dsi_ps_control_vact() to set:
    - Loosely Packed, 24-bits for MIPI_DSI_FMT_RGB666
    - Packed, 18-bits for MIPI_DSI_FMT_RGB666_PACKED

Fixes: 2e54c14e310f ("drm/mediatek: Add DSI sub driver")
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240215085316.56835-3-angelogioacchino.delregno@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index a2fdfc8ddb153..cd19885ee017f 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -71,8 +71,8 @@
 #define DSI_PS_WC			0x3fff
 #define DSI_PS_SEL			(3 << 16)
 #define PACKED_PS_16BIT_RGB565		(0 << 16)
-#define LOOSELY_PS_18BIT_RGB666		(1 << 16)
-#define PACKED_PS_18BIT_RGB666		(2 << 16)
+#define PACKED_PS_18BIT_RGB666		(1 << 16)
+#define LOOSELY_PS_24BIT_RGB666		(2 << 16)
 #define PACKED_PS_24BIT_RGB888		(3 << 16)
 
 #define DSI_VSA_NL		0x20
@@ -369,10 +369,10 @@ static void mtk_dsi_ps_control_vact(struct mtk_dsi *dsi)
 		ps_bpp_mode |= PACKED_PS_24BIT_RGB888;
 		break;
 	case MIPI_DSI_FMT_RGB666:
-		ps_bpp_mode |= PACKED_PS_18BIT_RGB666;
+		ps_bpp_mode |= LOOSELY_PS_24BIT_RGB666;
 		break;
 	case MIPI_DSI_FMT_RGB666_PACKED:
-		ps_bpp_mode |= LOOSELY_PS_18BIT_RGB666;
+		ps_bpp_mode |= PACKED_PS_18BIT_RGB666;
 		break;
 	case MIPI_DSI_FMT_RGB565:
 		ps_bpp_mode |= PACKED_PS_16BIT_RGB565;
@@ -426,7 +426,7 @@ static void mtk_dsi_ps_control(struct mtk_dsi *dsi)
 		dsi_tmp_buf_bpp = 3;
 		break;
 	case MIPI_DSI_FMT_RGB666:
-		tmp_reg = LOOSELY_PS_18BIT_RGB666;
+		tmp_reg = LOOSELY_PS_24BIT_RGB666;
 		dsi_tmp_buf_bpp = 3;
 		break;
 	case MIPI_DSI_FMT_RGB666_PACKED:
-- 
2.43.0