github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 10:09:10 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm/amd/display: Disable 10-bit truncation and dithering on DCE 6.x

Browse Source 
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: 529cad0f94 ("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>
This commit is contained in:
Timur Kristóf 2026-04-21 01:55:04 +02:00 committed by Alex Deucher
parent 9d47b2c36b
commit 6be8ced880
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/gpu/drm/amd/display/dc/core/dc_resource.c
View File

@ -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;