[PATCH] [ACPI] Default to using the native backlight control on Windows 8 systems

[Aaron Lu]

On 04/11/2014 06:58 PM, Jani Nikula wrote:
> On Fri, 11 Apr 2014, Aaron Lu <aaron.lu at intel.com> wrote:
>> On 04/11/2014 04:13 AM, Matthew Garrett wrote:
>>> The list of machines in the "Use native backlight" table is getting longer
>>> and longer, which is a solid indication that we're doing something wrong.
>>> Disable the ACPI backlight interface if the system claims to be Windows 8
>>> or later.
>>
>> And has a native backlight control interface.
> 
> This. One thing we were doing wrong in i915 was unconditionally
> registering a native backlight interface even when it was not
> functional. We can't really know whether that is the case except by
> trusting the VBT, and although we've been let down in the past, trusting
> the VBT on this one is probably a better approximation of the reality
> than assuming it always works. Thus we've queued [1] and [2] for 3.15
> which should help.
> 
> [1] http://cgit.freedesktop.org/drm-intel/commit/?id=39fbc9c8f6765959b55e0b127dd5c57df5a47d67
> [2] http://cgit.freedesktop.org/drm-intel/commit/?id=c675949ec58ca50d5a3ae3c757892f1560f6e896

That's pretty cool :-)

Regards,
Aaron