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@xxxxxxxxxxxx>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
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 c66e18006070..8af0afbe9e3d 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 GENMASK(13, 0)
#define DSI_PS_SEL GENMASK(17, 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
@@ -370,10 +370,10 @@ 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;
@@ -427,7 +427,7 @@ 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
