If anyone is running gentoo trying to get alsa working with the asus a7n8x deluxe this is how I did it.
I used 2.4.21-pre5-ac3 kernel (with amd viper for ide)
root@lieutenant uniplex # hdparm -i /dev/hda | grep -i udma
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 udma6
I followed the guide at http://www.gentoo.org/doc/en/alsa-guide.xml
only difference was for alsa-driver I did cd /usr/portage/media-sound/alsa-driver; emerge alsa-driver-0.9.1.ebuild This alsa driver worked. emerge alsa-driver didn't.
When I compiled the kernel I made soundcore a module and nothing else for sound. And I made sure it wasn't loaded when I did emerge alsa-driver-0.9.1.ebuild.