[Intel-gfx] BACKLIGHT_CONTROL and xrandr

[ykzhao]

On Wed, 2010-04-07 at 22:16 +0800, Sergio Monteiro Basto wrote:
> On Wed, 2010-04-07 at 08:36 +0800, ykzhao wrote: 
> > On Tue, 2010-04-06 at 23:43 +0800, Sergio Monteiro Basto wrote:
> > > Hi , I have fedora 12 updated , with kernel 2.6.32.11-99.fc12.i686.PAE ,
> > > with have new bits of drm by Arlied.  
> > > 
> > > Back to drv-intel 2.5.1 I wrote 
> > > "xrandr --output LVDS --set BACKLIGHT_CONTROL legacy, look like that
> > > fixes the issue. The difference about drv-intel 2.2.1 and drv-intel
> > > 2.5.1 , in this case, is only, the default BACKLIGHT_CONTROL value."
> > > 
> > > but now I can't even see BACKLIGHT_CONTROL properties . 
> > > 
> > > xrandr  --properties don't show any info for BACKLIGHT_CONTROL 
> > > am I missing something ? 
> > 
> > Can you confirm whether the brightness interface can be found
> > under /sys/class/backlight/*?
> no 
> 

Thanks for the response.

It is bad news that there is no generic ACPI backlight interface on this
box.

After switching to KMS, the backlight property depends on the ACPI
backlight interface. If no backlight interface is found
under /sys/class/backlight/, the backlight property can't be created.

Maybe on your box we should add one platform backlight interface(using
legacy control method) so that the backlight brightness can be
controlled for your box.

Thanks.

> ls -l /sys/class/backlight/
> total 0
> 
> This is an old (always the same) laptop with 4 years old 
> 
> Thanks, 
> 
> > If it exists, please confirm whether the brightness can be adjusted
> > by using the following command?
> >     echo XXX > /sys/class/backlight/*/brightness
> > 
> > thanks
> >     Yakui
> > > 
> > > 
> > > Thanks,
> > 
>