[Intel-gfx] Legacy backlight control with KMS and BACKLIGHT property

[Matthew Garrett]

On Fri, Aug 14, 2009 at 12:28:47PM -0700, Greg KH wrote:
> On Fri, Aug 14, 2009 at 12:08:21PM -0700, Greg KH wrote:
> > Here's a first cut at such a driver.  It works for me on this laptop,
> > but note that it will try to work on _any_ Intel-based system.  I'll
> > figure out how to do this only for specific machines based on DMI data
> > next.
> 
> And here's one that is set for DMI data to only load on the proper ones.
> 
> I'll push this upstream now, if there are no objections.

This seems basically right, but I don't think DMI's the correct 
approach. We should be trying the registers on any device that doesn't 
implement the ACPI code and doesn't provide a more generic 
platform-specific interface. Speaking of which, are we sure there isn't 
a Samsung-specific interface? Using a platform interface is always 
preferable to hitting the registers directly, since that way we don't 
have the firmware getting out of sync with the hardware.

-- 
Matthew Garrett | mjg59 at srcf.ucam.org