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 "panel power saving". This property is an enum that can be configured by the compositor to "Allowed" or "Forbidden". When a driver advertises support for this property and the compositor sets it to "Forbidden" 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 "Forbidden" then this feature will be disabled and any userspace that tries to turn it on will get an -EBUSY return code. When the compositor has restored the value back to "Allowed" then the previous value that would have been programmed will be restored. Mario Limonciello (2): drm: Introduce panel_power_saving drm property drm/amd: Add panel_power_saving drm property to eDP connectors drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 3 ++ .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 34 ++++++++++++++--- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 1 + drivers/gpu/drm/drm_connector.c | 37 +++++++++++++++++++ include/drm/drm_connector.h | 1 + include/drm/drm_mode_config.h | 6 +++ include/uapi/drm/drm_mode.h | 4 ++ 7 files changed, 81 insertions(+), 5 deletions(-) -- 2.45.0
