drm/amd/display: Fix HF-VSDB DSC bpc detection to be cumulative

Browse source

[Why & How]
The HDMI Forum VSDB reports the maximum DSC color depth a sink supports.
This maximum is cumulative: a sink that reports 12 bpc also supports 10
and 8 bpc.

The previous code used exact "== 10" and "== 12" comparisons chained with
else-if, so a 12 bpc sink only set frl_dsc_12bpc and never set
frl_dsc_10bpc, incorrectly narrowing the DSC bpc range usable with that
sink.

Use ">= 10" and a separate ">= 12" check so a sink advertising a higher
maximum also enables the lower DSC bit depths it supports.

Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 4523adbf4d)

...

This commit is contained in:

Fangzhi Zuo 2026-08-26 17:47:41 -04:00 • committed by Alex Deucher

parent 3001d2073d

commit 5d7e0cc4af

2 changed files with 4 additions and 3 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c

View file

2

drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c

View file