BOE 2270 panel is used by several models of ThinkPads.
This brightness can not be controlled by default PWM.
The panel claims both PWM and AUX supports.
But actually PWM works on SDR mode, AUX works on HDR mode.
Intel i915 driver got a new SDR support to use PWM by maintainer, still
in upstream review.
To fix this on certain project, use a quirk first to fix this.
The maintainer's fix can be backported in future.
Backlight brightness can be changed.
Fix for specific panel ID, no effects for others.
Since this is temporary quirk, it will go to oem-5.6 only.
Aaron Ma (1):
UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode for BOE 2270 panel