I'm on a Geode LX 500mhz laptop. As you might imagine, this machine is lacking in processing power. ALSA on the Geode LX/CS5536 chipset is abysmal... stuttering audio at best, and 100% CPU usage are all I can get. Throw in Pulseaudio for more of the same.
I've found OSS4 allows me to listen to MP3s and MPlayer movies, and leaves plenty of CPU to boot (albeit only 1 audio stream at a time, which is fine).
OSS4 worked great under 2.6.32 kernels, but Maverick Meerkat aka Ubuntu 10.10 ships with the much better 2.6.35 kernel. I've yet to get a working OSS4 setup, with either the broken-hasn't-worked-ever-why-is-it-in-the-repositories Ubuntu repository OSS4 packages, nor the worked-before .deb from 4front's opensound.com site.
It builds and installs fine, but doesn't start up correctly. No audio and warnings of no mixer.
Any ideas? I suspect I will have to wait for 4front to release a working .deb
lsmod | grep oss reports:
Version info: OSS 4.2 (b 2003/201007311944) (0x00040100) GPL
Platform: Linux/i586 2.6.35-22-generic #34-Ubuntu SMP Sun Oct 10 09:24:00 UTC 2010 (kjsa)
Number of audio devices: 0
Number of audio engines: 0
Number of MIDI devices: 0
Number of mixer devices: 0
0: osscore0 OSS core services
1: oss_usb0 USB audio core services
MIDI devices (/dev/midi*)
oss_usb 92545 0
oss_geode 8451 0
osscore 541033 2 oss_usb,oss_geode