Bug#595767: Won't load hardware acceleration after system start

[Michel Dänzer]

On Die, 2010-11-09 at 23:40 +0100, Ivan Vilata i Balaguer wrote: 
> Alex Deucher (2010-10-07 12:58:34 -0400) wrote:
> 
> > On Wed, Oct 6, 2010 at 6:17 AM, Ivan Vilata i Balaguer <ivan at selidor.net> wrote:
> > > Cyril Brulebois (2010-10-05 19:12:12 +0200) wrote:
> > >
> > >> Please install 2.6.32 kernel from sid, boot it with KMS enabled, and
> > >> send both kernel & X logs so that we can determine why DRI doesn't
> > >> work out of the box in that case.
> > >
> > > Done.  Here you have both log files.
> > 
> > You have radeonfb loaded which is claiming the device preventing the
> > kms drm from loading.
> 
> How should I disable it?
> 
> (Also, people report at #587999 that disabling radeonfb makes the computer
> unusable.)

As mentioned in the referenced bug report, you can disable radeonfb with
video=radeonfb:off or disable KMS with radeon.modeset=0.

The problems with KMS mentioned in that report weren't substantiated
with specific information. The biggest known gotchas right now are:

      * radeon.agpmode=1 (or even radeon.agpmode=-1) may be needed for
        KMS to be stable on PowerMacs. 
      * On laptops there's no backlight control and no suspend to RAM
        support yet.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer