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| author | Fangzhi Zuo <jerry.zuo@amd.com> | 2026-08-26 17:47:41 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-09-10 12:03:04 -0400 |
| commit | 4523adbf4dca157aea96a6f28b4e7b7ebd4d5eda (patch) | |
| tree | 82a94ff0ca2b5500e67954d616f4389221d6f56f | |
| parent | 86420fe3093161971b4064e05be11ffff1df76aa (diff) | |
| download | linux-next-4523adbf4dca157aea96a6f28b4e7b7ebd4d5eda.tar.gz linux-next-4523adbf4dca157aea96a6f28b4e7b7ebd4d5eda.zip | |
drm/amd/display: Fix HF-VSDB DSC bpc detection to be cumulative
[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>
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 5 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c | 2 |
2 files changed, 4 insertions, 3 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index 93fd5f251a6c..836c06772a68 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -1228,9 +1228,10 @@ void populate_hdmi_info_from_connector(bool enable_frl, struct drm_hdmi_info *hd edid_caps->max_frl_rate = get_max_frl_rate(hdmi->max_lanes, hdmi->max_frl_rate_per_lane); edid_caps->frl_dsc_support = hdmi->dsc_cap.v_1p2; if (edid_caps->frl_dsc_support) { - if (hdmi->dsc_cap.bpc_supported == 10) + /* HF-VSDB DSC max bpc is cumulative: >=12 implies 10 and 8. */ + if (hdmi->dsc_cap.bpc_supported >= 10) edid_caps->frl_dsc_10bpc = true; - else if (hdmi->dsc_cap.bpc_supported == 12) + if (hdmi->dsc_cap.bpc_supported >= 12) edid_caps->frl_dsc_12bpc = true; edid_caps->frl_dsc_all_bpp = hdmi->dsc_cap.all_bpp; edid_caps->frl_dsc_native_420 = hdmi->dsc_cap.native_420; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c index d4232648d8e6..ceedb8745267 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_helpers_test.c @@ -982,7 +982,7 @@ static void dm_test_populate_hdmi_frl_dsc_12bpc(struct kunit *test) KUNIT_EXPECT_EQ(test, caps->max_frl_rate, 2); KUNIT_EXPECT_TRUE(test, caps->frl_dsc_support); - KUNIT_EXPECT_FALSE(test, caps->frl_dsc_10bpc); + KUNIT_EXPECT_TRUE(test, caps->frl_dsc_10bpc); KUNIT_EXPECT_TRUE(test, caps->frl_dsc_12bpc); KUNIT_EXPECT_EQ(test, caps->frl_dsc_max_slices, 7); KUNIT_EXPECT_EQ(test, caps->frl_dsc_max_frl_rate, 1); |