[Intel-gfx] BACKLIGHT property for KMS case

[ykzhao]

On Tue, 2009-08-18 at 10:05 +0800, Matthew Garrett wrote:
> On Tue, Aug 18, 2009 at 10:00:43AM +0800, ykzhao wrote:
> 
> > Another issue is that the brightness level is so big when the
> > native/combo mode is used. For example: 0-65535 for the native control
> > method. The user will be confused by so many brightness levels.
> 
> There's no problem with this for userspace. We don't show every single 
> value to the user, but it's helpful if the driver exposes everything it 
> can do.
> 
> > How about using the legacy control method?
> 
> If the firmware touches the BLC registers and we just touch the legacy 
> registers then things will become very confused.
Yes. If the brightness can be adjusted through two different interfaces,
there exists the inconsistence. So we had better expose only one
backlight interface under /sys/class/backlight. 

Thanks.
  
>