Bug 11626

Summary: Intel driver (using EXA) crashes system when starting compiz
Product: xorg Reporter: Conn <psyke>
Component: Server/Acceleration/EXAAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED NOTOURBUG QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: git   
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
dmesg log
none
xorg.conf (exa and greedy heuristic enabled)
none
Xorg.0.log
none
xorg.conf (xaa and xaanooffscreenpixmaps)
none
Xorg.0.log (xaa accelmethod) none

Description Conn 2007-07-16 12:30:04 UTC
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 2:1.3.0.0.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.

/proc/mtrr:
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
Comment 1 Conn 2007-07-16 12:30:37 UTC
Created attachment 10759 [details]
dmesg log
Comment 2 Conn 2007-07-16 12:31:58 UTC
Created attachment 10760 [details]
xorg.conf (exa and greedy heuristic enabled)
Comment 3 Conn 2007-07-16 12:32:43 UTC
Created attachment 10761 [details]
Xorg.0.log
Comment 4 Conn 2007-07-16 12:34:55 UTC
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.
Comment 5 Conn 2007-07-16 12:42:53 UTC
Created attachment 10762 [details]
xorg.conf (xaa and xaanooffscreenpixmaps)
Comment 6 Conn 2007-07-16 12:45:24 UTC
Created attachment 10763 [details]
Xorg.0.log (xaa accelmethod)

Relevant excerpt:

(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?
Comment 7 Conn 2007-07-16 13:51:30 UTC
Resolved.

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).

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