psm0 lockup on boot (FreeBSD 4.9 PreRelease #2)

[Patrick C]

> I lost the previous thread on the psm0 lock but also wanted to report that
> after cvsup-ing for the arp patch and rebuilding that the lockup still
> occurs, any leads on a fix/workaround? (Besides removing psm0 or disabling
> the sound card).

I had the same problem where my kernel would lock up until I changed the 
soundcard PCI slot -- as well as my network card -- and assigned irqs to each 
of those slots and my video card. This appears to be because of irq 
conflicts. Here's what I found this in the LINT file:

# Note: It has been reported that ISA DMA with the SoundBlaster will
# lock up the machine (PR docs/5358).  If this happens to you,
# turning off USWC write posting in your machine's BIOS may fix
# the problem.

That fixed it for me.