panic in drm

[Gavin Atkinson]

On Thu, 2008-06-26 at 16:09 +0200, Ronald Klop wrote:
> Hello,
> 
> At my work I see a panic if I do this.
> Leaf my computer on screensaver (don't no if that is necessary) and come  
> back the next morning. My monitor is than black, but the light is green,  
> so DPMS didn't kick in.
> Keys or mouse don't wake up the system. CTRL-ALT-F1 switches to the  
> console and immediately triggers this panic.
> 
> I'm running latest x.org with xf86-video-i810-1.7.4_1. The newer  
> xf86-video-intel also crashes my system sometimes when I'm working on it,  
> so a downgraded.
> 
> Any ideas, suggestions or fixes available?

This sounds very familiar to me.  I think I was seeing the same panic in
2006...
http://unix.derkeiler.com/Mailing-Lists/FreeBSD/stable/2006-12/msg00344.html

Can you add this to src/sys/dev/drm/i915_irq.c

if (!dev->irqr) {
  return DRM_ERR(EINVAL);
}

just above the DRM_WAIT_ON in i915_driver_vblank_wait() (around line
140), and see if that prevents the panic?  Note that I believe this to
be a workaround, and not really the correct fix.

(sorry for not supplying patches, I'm not in a position to right now)

Gavin