Hello,
I saw in the devel archive that the support for VIA VT2020 chipset have been added and merged to 1.0.22 released. (cf. http://mailman.alsa-project.org/pipermail/alsa-devel/2009-October/022183.htm... and http://www.alsa-project.org/main/index.php/Changes_v1.0.21_v1.0.22 )
Unfortunately, despite all was OK from the 1.0.21+git devel snapshot few month ago, the alsa-driver v1.0.22 doesn't work. I tried different snapshot from 1.0.22, and sent a bug report here : https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4857
I don't know what I can do more to resolve the bug, but I can make some other tests and give you more log if needed.
NB : I don't subscribe the devel mailing list, but I am "monitoring" the above bug report.
Thank's in advance. Best Regards, draco