ACK/Cmnt: [OEM-5.17/J][PATCH 0/3] Fix oled brightness set above frame-average luminance

Aaron Ma aaron.ma at canonical.com
Wed Aug 24 08:45:46 UTC 2022



On 8/24/22 16:03, Stefan Bader wrote:
> On 23.08.22 16:50, Aaron Ma wrote:
>> BugLink: https://bugs.launchpad.net/bugs/1978986
>>
>> [Impact]
>> The brightness is not changed obviously during 200 to 255 on AMD
>> or 400 to 512 on Intel.
>>
>> [Fix]
>> Read HDR meta to detect the max and min luminance.
>> max_cll defines the content light luminance for individual pixel.
>> max_fall defines frame-average level luminance.
>> Use max_fall value instead of max_cll as a limit for brightness control.
>>
>> [Test]
>> Verified on AMD Cezanne, Barcelo, Rembrandt and Intel ADL, also on LCD panel and
>> OLED panel. The brightness is changed more obivously on OLED panel, and
>> no affect on LCD panel.
>>
>> [Where problems could occur]
>> Low risk, It may cause the max brightness can't be set.
>>
>> All 3 patches are in drm-misc tree.
>>
>> Jouni Högander (3):
>>    UBUNTU: SAUCE: drm: New function to get luminance range based on
>>      static hdr metadata
>>    UBUNTU: SAUCE: drm/amdgpu_dm: Rely on split out luminance calculation function
>>    UBUNTU: SAUCE: drm/i915: Use luminance range calculated during edid parsing
>>
>>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 35 ++-----------
>>   drivers/gpu/drm/drm_edid.c                    | 52 ++++++++++++++++++-
>>   .../drm/i915/display/intel_dp_aux_backlight.c | 15 +++++-
>>   include/drm/drm_connector.h                   | 21 ++++++++
>>   4 files changed, 89 insertions(+), 34 deletions(-)
>>
> 
> Am I understanding right that this is something to allow oem-5.14 to roll forward? In which case I would like to see more info in future on
> - how long has this been in oem-5.14 (regressions?)
> - why is this not yet upstream?
> 

The fix of AMD part is already landed in upstream and in oem-5.14 for 2 month.
This new version included Intel fix, it just landed in drm-misc and drm-tip.
It should be expected in 6.0.

Aaron

> Acked-by: Stefan Bader <stefan.bader at canonical.com>
> 



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