[PATCH v4 0/2] Add support for 'power saving policy' property

Hamza Mahfooz hamza.mahfooz at amd.com
Wed Jul 10 21:01:22 UTC 2024


On 7/3/24 01:17, Mario Limonciello wrote:
> During the Display Next hackfest 2024 one of the topics discussed
> was the need for compositor to be able to relay intention to drivers
> that color fidelity is preferred over power savings.
> 
> To accomplish this a new optional DRM property is being introduced called
> "power saving policy".  This property is a bit mask that can be configured
> with requests of "Require color accuracy" or "Require low latency"
> that can be configured by the compositor.
> 
> When a driver advertises support for this property and the compositor
> sets it to "Require color accuracy" then the driver will disable any power
> saving features that can compromise color fidelity.
> 
> In practice the main feature this currently applies to is the
> "Adaptive Backlight Modulation" feature within AMD DCN on eDP panels.
> 
> When the compositor has marked the property  "Require color accuracy" then
> this feature will be disabled and any userspace that tries to turn it on
> will get an -EBUSY return code.
> 
> Compositors can also request that low latency is critical which in
> practice should cause PSR and PSR2 to be disabled.
> 
> When the compositor has restored the value back to no requirements then
> the previous value that would have been programmed will be restored.

Applied, thanks!

> 
> v3->v4:
>   * Fixup for Xaver's reported issue
> v2->v3:
>   * Updates from Leo's comments (see individual patches)
> 
> Mario Limonciello (2):
>    drm: Introduce 'power saving policy' drm property
>    drm/amd: Add power_saving_policy drm property to eDP connectors
> 
>   drivers/gpu/drm/amd/amdgpu/amdgpu_display.c   |  4 ++
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 50 +++++++++++++++++--
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  2 +
>   drivers/gpu/drm/drm_connector.c               | 48 ++++++++++++++++++
>   include/drm/drm_connector.h                   |  2 +
>   include/drm/drm_mode_config.h                 |  5 ++
>   include/uapi/drm/drm_mode.h                   |  7 +++
>   7 files changed, 113 insertions(+), 5 deletions(-)
> 
-- 
Hamza



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