drm locking up the desktop?

[Paul Schmehl]

I recently upgraded to 6.2 release (i386) on my desktop workstation, and 
I'm experiencing occasional lockups that require restarting X to resolve. 
I can ssh in to the box and kill the process and force a restart, but the 
desktop is completely unusable - both mouse and keyboard don't function - 
so I can't restart X with Ctrl-Alt-Bkspc.  When I ssh in, performance is 
normal and top doesn't show any unusual memory or CPU usage.  PID974 was 
the pid for X.

I found these errors in /var/log/messages:
Dec 12 09:36:51 utd59514 kernel: error: [drm:pid974:drm_lock_take] *ERROR* 
1 holds heavyweight lock
Dec 12 09:36:51 utd59514 kernel: error: [drm:pid974:drm_lock_take] *ERROR* 
1 holds heavyweight lock

Although these showed up on the 12th, the desktop just locked up a few 
minutes ago, so they *may* be unrelated.  I tried unloading drm (kldunload 
drm.ko), but that failed.

When I grep the Xorg log I see these errors:
root at utd59514# grep EE /var/log/Xorg.0.log
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(II) Loading extension MIT-SCREEN-SAVER
(EE) RADEON(0): Unable to write to DVO Slave 112.
(EE) RADEON(0): Unable to write to DVO Slave 112.
(EE) RADEON(0): Unable to write to DVO Slave 112.

I don't know if these are related to the problem either.  I'm wondering 1) 
has anybody else experienced this problem and 2) does anyone have any 
suggestions as to where to start looking for the answer?

-- 
Paul Schmehl (pauls at utdallas.edu)
Senior Information Security Analyst
The University of Texas at Dallas
http://www.utdallas.edu/ir/security/