Re: enabling kms for i915 disables brightness control and xrandr

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Mon, 30 Mar 2009 15:37:19 +0200
Soeren Sonnenburg <sonne@debian.org> wrote:

> 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.

Have you filed bugs for these problems?  I think the brightness control
issue is due to some missing bits on the 2D side (we don't enable
backlight property control when KMS is active, but should), the other
issues sound like bugs.

-- 
Jesse Barnes, Intel Open Source Technology Center