Bug#484583: xserver-xorg-video-nv: Failed to set up write-combining range

[Brice Goglin <Brice.Goglin@ens-lyon.org>]

Ryo Furue wrote:
> Package: xserver-xorg-video-nv
> Version: 1:2.1.9-1
> Severity: normal
>
> I have this warning in my /var/log/Xorg.0.log :
>
>   (WW) NV(0): Failed to set up write-combining range (0xd8000000,0x8000000)
>
> and this in /var/log/kern.log
>
>    kernel: mtrr: type mismatch for d8000000,8000000 old: write-back new: write-combining
>   

Not sure this is actually a bug. The kernel is mainly responsible for
marking ranges as WC. But sometimes there are too many entries allocated
so Xorg cannot get a new one. And sometimes, the existing ranges are
difficult to modify to satisfy what Xorg wants.

What does /proc/mtrr contains before and after starting X?

Brice