System: Dell Inspiron 510m laptop, Intel(R) Pentium(R) M processor 1500MHz, 512mb RAM,
Display controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02).
OS: Ubuntu Gutsy; xserver-xorg-core 2:126.96.36.199.dfsg-6ubuntu2, xserver-xorg-video-intel 2:2.1.0-1ubuntu1
Issue: Intel driver (using EXA) crashes system when starting compiz
Steps to reproduce (always):
1. Start GNOME session, ensuring that '"AccelMethod" "exa"' is enabled in xorg.conf
2. Start compiz (via wrapper script or directly, passing various or no options makes no difference)
3. Screen either blanks or displays corrupt/vertical coloured lines, and system freezes
Notes (most relevant first):
1. Compiz with XAA works fine & with no crashes
2. Direct Rendering works perfectly for both EXA and XAA (i.e. ppracer etc. works the same in either situation and glxinfo | grep -i direct returns "yes" in both cases)
3. I experience the same crash on my desktop (Intel 865G chipset), and despite the same freeze occuring, it's possible to access the machine via ssh - however nothing is reported in dmesg or Xorg.0.log after compiz crashes.
4. Up until a recent update, EXA by default was causing some graphical glitches (corruption, noticeable with gnome-panel and openoffice.org in particular) unless I added '"MigrationHeuristic" "greedy"' to xorg.conf. I no longer see these issues anymore, but keep the greedy heuristic enabled as it's much faster.
Relevant logs will be attached.
reg00: base=0x00000000 ( 0MB), size= 512MB: write-back, count=1
reg01: base=0x1ff00000 ( 511MB), size= 1MB: uncachable, count=1
reg02: base=0xfeda0000 (4077MB), size= 128KB: write-through, count=1
reg03: base=0xf0000000 (3840MB), size= 128MB: write-combining, count=1
Created attachment 10759 [details]
Created attachment 10760 [details]
xorg.conf (exa and greedy heuristic enabled)
Created attachment 10761 [details]
A note regarding my logs: I did not attempt to start compiz, as the system freezes and I cannot access any logs.
If you would like the specs and logs of my desktop system (Intel 865G, which seems to survive from this same crash), I'll be happy to oblige.
Created attachment 10762 [details]
xorg.conf (xaa and xaanooffscreenpixmaps)
Created attachment 10763 [details]
Xorg.0.log (xaa accelmethod)
(II) XAA: Evicting pixmaps
Michel Danzer mentioned in another bug that it's a bad patch in Ubuntu's xserver-xorg-core, can anyone name the offending patch so I can recompile and test without it?
Recompiling xorg-xserver source package without 120_fedora_disable_offscreen_pixmaps.diff has solved the problem, EXA & Compiz now function together. Unfortunately, restarting X/switching to VTs while Compiz is active causes my system to hang (but this happens also with XAA, so it's a matter for another bug).