I am unable to figure out what's wrong with my setup. Essentially, Xorg tells me DRI is enabled, and so does xdriinfo; glxinfo, on the other hand, says that dri is not enabled. PPracer and the various GL games hardly run.

Let me quote the relevant portion of the Xorg log and the glxinfo output.

root@alex:~# grep -i 'dri' /var/log/Xorg.0.log
X.Org Video Driver: 0.8
X.Org XInput driver : 0.5
ABI class: X.Org Video Driver, version 0.8
ABI class: X.Org Video Driver, version 0.8
(II) LoadModule: "dri"
(II) Loading /usr/lib/xorg/modules/extensions/libdri.so
(II) Module dri: vendor="X.Org Foundation"
(II) Loading extension XFree86-DRI
ABI class: X.Org Video Driver, version 0.8
(II) Loading /usr/lib/xorg/modules/drivers/v4l_drv.so
ABI class: X.Org Video Driver, version 0.8
ABI class: X.Org Video Driver, version 0.8
(II) Loading /usr/lib/xorg/modules/drivers/i810_drv.so
Module class: X.Org Video Driver
ABI class: X.Org Video Driver, version 0.8
Module class: X.Org XInput Driver
ABI class: X.Org XInput driver, version 0.5
Module class: XFree86 XInput Driver
ABI class: XFree86 XInput driver, version 0.3
Module class: X.Org XInput Driver
ABI class: X.Org XInput driver, version 0.5
(II) v4l driver for Video4Linux
(II) I810: Driver for Intel Integrated Graphics Chipsets: i810, i810-dc100,
ABI class: X.Org Video Driver, version 0.8
ABI class: X.Org Video Driver, version 0.8
ABI class: X.Org Video Driver, version 0.8
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: node name is /dev/dri/card0
(II) I810(0): [drm] loaded kernel module for "i915" driver
(II) I810(0): [drm] created "i915" driver at busid "pci:0000:00:02.0"
(II) I810(0): [dri] visual configs initialized
(II) I810(0): [DRI] installation complete
(II) Synaptics touchpad driver version 0.14.5 (1405)

alex@alex:~$ glxinfo | grep -i direct
direct rendering: No
OpenGL renderer string: Mesa GLX Indirect

alex@alex:~$ ll /dev/dri/*
crw-rw-rw- 1 root video 226, 0 2006-06-22 14:56 /dev/dri/card0
crw-rw-rw- 1 root video 226, 1 2006-06-22 14:56 /dev/dri/card1


What's going on?

Alex

Here's the deal: the recent update to xorg 7 in Debian Testing required some manual reinstalling of X related packages. I had not noticed that because of this update I needed to manually reinstall libgl-mesa-dri. Without this package the Xorg driver for the i915 3D accelerator is active ("direct rendering enabled" in the xorg log file), but the clients cannot find the appropriate shared object to "speak" DRI with the graphics processor.

Once I solved this issue, 3D games such as Tuxkart have come back to life.