DRI with ATI graphics chip

[Thomas Schlesinger]

Hi,

I've seen, there's a drm module in the source code. 

I use an ATI Mobility X600 PCIe chip in my notebook. I've loaded the radeon.ko 
module and have an empty directory /dev/dri, but the Xorg.0.log tells me:
[..]
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is -1, (Device not configured)
drmOpenDevice: open result is -1, (Device not configured)
drmOpenDevice: Open failed
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is -1, (Device not configured)
drmOpenDevice: open result is -1, (Device not configured)
drmOpenDevice: Open failed
[drm] failed to load kernel module "radeon"
(II) RADEON(0): [drm] drmOpen failed
(EE) RADEON(0): [dri] DRIScreenInit failed.  Disabling DRI.
[..]

Can somebody please point me to a documentation about setting up DRM/DRI or 
give me some hints?

Thanks,
Thomas