Xorg (i810) freezes randomly when using hardware accel

[Stephen Montgomery-Smith]

Markus Hoenicka wrote:
> Hi,
> 
> I'm running FreeBSD 6.1 on a MSI260 subnotebook. It's a Centrino thing using the
> 915GM chipset. Xorg is running (mostly) alright using the current 6.9.0 ports.
> However, I suffer from random freezes when running programs that apparently try
> to use hardware acceleration. I see this e.g. when watching movie clips with
> Xine. This is not a problem with the clips themselves. They run ok a couple of
> times, then they randomly freeze X.
> 
> This happens only if I use the i810 driver. I can run X just as well with the
> Vesa driver (without hardware acceleration). The frame rates are lower, but X
> is rock solid. It also never freezes if I use only applications that do not use
> hardware acceleration.
> 
> The real bad thing is that after the i810 driver freezes X, I can't access the
> console anymore. Pressing Ctrl+Alt+backspace sometimes alters the frozen
> display to a modern-art style random pattern, but the box does not react to
> further keypresses, and the display never leaves graphics mode. FreeBSD is
> still running happily underneath as I can log in from a remote box without a
> hitch. The process list shows that all X-related stuff is gone, except a font
> server.
> 
> My two questions:
> 
> 1) is there anything I can do to prevent the crashes in the first place?
> 
> 2) if it has to crash anyway, is there a magic incantation (even if I have to
> log in remotely) to activate the console again? Having to reboot makes me feel
> like running Windows.

Interestingly enough I get exactly the same problem with my desktop 
system with an Nvidia graphics card.  The only difference is that when I 
log on remotely, top shows Xorg running with close to 100% cpu. 
"killall -9 Xorg" fixes the problem for me, but it is not a satisfactory 
solution.