PROBLEM: Oops when running Xorg with KMS

[Michał P. <mic...@gm...>]

Hi.
I'm running Source Mage GNU/Linux on an Acer Aspire 3690 with following configuration:

Celeron Yonah 1.6
Intel 945GM w/ integrated graphics
Linux 2.6.29-rc3 (I also tried rc3-git5, but nothing changed)
libdrm 2.4.4
mesa 7.3
xorg-server 1.5.3 (tried 1.5.99.902)
xf86-video-intel 2.6.1

Without KMS X seems to work fine, but otherwise things are getting weird. The first time I run Xorg, it works with some glitches:

1. Screen is 1280x800 (native resolution of my LCD), but for some reason Xorg changes LVDS mode to 1024x768, displaying only upper-left part of the desktop. Xrandr knows about this mismatch and it is possible to switch LVDS back to 1280x800. VT switching works in both modes and in 1280x800 it is much faster than it used to be, so I assume that KMS works fine.

2. 3D rendering performs very poorly. glxgears gives ~0.928 fps and prints this message:
do_wait: drmWaitVBlank returned -1, IRQs don't seem to be working correctly.
Try adjusting the vblank_mode configuration parameter.

When I exit X and try to start it again, I get a black screen and an oops in dmesg.

Attachments:
log1, log2 - Xorg.0.log from 1st and 2nd run
config - kernel .config
lspci - output from lspci -vvv
xorg.conf
dmesg - collected after oops. Timeline:
  [  41 ] - starting X for the 1st time
  [  82 ] - end of 1st session
  [ 283 ] - starting X for the 2nd time