Re: enabling kms for i915 disables brightness control and xrandr

Soeren Sonnenburg
2009-03-30T13:37:37Z

On Sun, 2009-03-29 at 15:22 +0200, Soeren Sonnenburg wrote:
> On Sun, 2009-03-29 at 14:07 +0100, Sitsofe Wheeler wrote:
> > (CC'ing dri-devel, Eric Anholt and Jesse Barnes)
> >
> > On Sun, Mar 29, 2009 at 12:34:01PM +0200, Soeren Sonnenburg wrote:
> > > Dear all,
> > >
> > > I am not sure if this is just a user error/ too old userspace problem,
> >
> > [User stated that 2.6.3 intel driver is being used in another email]
>
> Just to not cause any (further?) confusion, I was using 2.6.1 when I
> wrote that email and after compiling/upgrading to 2.6.3 a number of
> problems vanished (like Xv works, screen resolution is correct, things
> are *a lot* faster with UXA). However, brightness still only works via
> setpci and xrandr only shows the 1024x600 modeline.
>
> > > but I recognized that when I enable kernel based modesetting on a intel
> > > 945 based samsung nc 10 netbook, I loose brightness control from within
> > > X and X resolutions are wrong (instead of 1024x600 it is 1024x1024) and
> > > xrandr does no longer have the all the modelines ranging from 1024x600
> > > to 640x350... Trying to change resolutions / setting the brightness via
> > > xrandr results in error messages being printed.
> > >
> > > Furthermore, this same flag disables Xv support..
> > >
> > > However, screen switches between terminal and X are quite fast now
> > > (without any flicker) and suspend and everything works stably.
> > >
> > > I recognized that I can set the brightness via
> > >
> > > setpci -s 00:02.1 F4.B=XX
> > >
> > > (XX ranging from 00 to FF) just fine...

One more thing: Connecting an external display I could turn it on via
xrandr --auto successfully. However, it was not possible to turn the
internal display off (xrandr --output LVDS1 --off) and switching to the
console with the external display connected I managed to freeze the
machine. Turning the external display off worked somehow (the display
then showed vertical stripes) but I could switch to console.

Soeren.