I got a new PowerMac G5 Quad a couple of weeks ago. Nice machine, except for the weak graphics and non-existent sound support on Linux.
The built-in sound card is completely unsupported at this time. As I did not feel like writing a driver for it, I plugged in an old USB sound device (Creative Sound Blaster Audigy 2 NX). At first this did not work, I just got oopses. But with a small fix (included in the kernel since 188.8.131.52) it started to work.
Next I tried to set up ALSA‘s dmix plug-in with S16 which resulted in horrible crackling: The byte swapping code was broken.
softvol plug-in (not strictly necessary but nice to have with GNOME’s volume control applet) didn’t work, it did not support any format available with snd-usb-audio on big-endian machines.
Here are the fixes for these two problems (against alsa-lib-1.0.11rc3):
If somebody is interested, here is the USB-Audio.conf I use with my Audigy 2 NX.
By the way: Is it normal that the
dmix plug-in consumes 100% CPU?
April 9th, 2006: The patches have been integrated into alsa-libs 1.0.11rc4, the 100% CPU issue is fixed in that version too.
There’s also a ALSA driver for the chip in the PowerMac Quad now, see this mail from Johannes Berg.