[Intel-gfx] [RFC PATCH 0/2] i915 brightness control

[Kamal Mostafa]

Requesting comments on this idea (proposed by Matthew Garrett) and my
implementation.  Note especially the KNOWN PROBLEM with a "GM45" GPU.

 -Kamal

.......

BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611

In order to avoid the often-dysfunctional native acpi brightness control
methods, a new acpi_brightness_hook interface is made available.

The i915 driver uses the new hook to take over brightness control.
Boot with i915.brightness=0 to disable.

KNOWN PROBLEM:
  - i915 opregion brightness control silently fails on GM45 (pci-id 0x2a42)

[RFC PATCH 1/2] acpi/video: acpi_brightness_hook API
[RFC PATCH 2/2] drm/i915: override acpi brightness control