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| author | Timur Kristóf <timur.kristof@gmail.com> | 2026-04-21 01:55:04 +0200 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-04-21 16:55:02 -0400 |
| commit | 6be8ced880dfe29ce38c2d5e74489822da5c250e (patch) | |
| tree | e52e457602aa2fc3f3dc0871997ff17b484c5e62 | |
| parent | 9d47b2c36b9a6c6b844c33cab407a5d7ad102234 (diff) | |
| download | linux-6be8ced880dfe29ce38c2d5e74489822da5c250e.tar.gz linux-6be8ced880dfe29ce38c2d5e74489822da5c250e.zip | |
drm/amd/display: Disable 10-bit truncation and dithering on DCE 6.x
DCE 6.x doesn't support 10-bit truncation and 10-bit dithering
because the following fields are 1-bit only:
FMT_TEMPORAL_DITHER_DEPTH
FMT_SPATIAL_DITHER_DEPTH
FMT_TRUNCATE_DEPTH
Programming these fields to "2" will program them as if the
dithering option was 6-bit, resulting in sub-par picture
quality and an ugly "color banding" effect.
Note that a recent commit changed the default 10-bit dithering
option to DITHER_OPTION_SPATIAL10 which improves the picture
quality because it happens to look better, but is still not
actually supported by DCE 6.x versions.
When the color depth is 10-bit or more, just disable
any kind of dithering options on DCE 6.x.
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5151
Fixes: 529cad0f945c ("drm/amd/display: Add function to set dither option")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c index 19526a278b2a..1ab76c2d0f72 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c @@ -5069,6 +5069,12 @@ void resource_build_bit_depth_reduction_params(struct dc_stream_state *stream, } } + if (stream->ctx->dce_version < DCE_VERSION_8_0 && + stream->timing.display_color_depth >= COLOR_DEPTH_101010) { + /* DCE 6.x doesn't support 10-bit truncation or dither options. */ + option = DITHER_OPTION_DISABLE; + } + if (option == DITHER_OPTION_DISABLE) return; |