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

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[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>

...

This commit is contained in:

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

parent 86420fe309

commit 4523adbf4d

2 changed files with 4 additions and 3 deletions

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5

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

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2

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

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