Using ppc-kernel-sources 2.4.19-r6 and alsa-0.9.0_rc5 from the ebuild with the snd-powermac module on an iBook2 (dual usb, 600MHz). Loading the ALSA modules will sometimes generate an OOPS, but the machine stays running.... once the modules are loaded, using anything to write to the sound device instantly panics the kernel and hangs the machine.
What is in your kernel configs? Do you have any other sound stuff i there at all, and is alsa configured correctly on the local machine?
Clee: Don't bother with alsa, I'm going to permanently set -ppc on it, they upstream guys can never get it right and it works on about 20% of ppc machines if we are lucky. None of my ppc hardware is capable of running alsa so I cannot test. sorry