There's been a bug on this chip's driver for at least four years.

https://bugtrack.alsa-project.org/alsa-bug/view.php?id=305

There are two ThinkPad 600X's in my home that have the problem. The chip is also in the ThinkPad A20m, A20p, A21m, A21p, A22m, A22p, T20, T21 and T22... and probably other brands as well.

In the 600X, it happens to be paired with a CS4297A... hey, should I just try to get Linux to use that? (I use Fedora BTW.) How would I try to do that?

Or... better still... how would I get either the '97A driver installed automatically by soundcard detection, or failing that, actually fix the driver? (I am a software developer who has written machine code for fun.)

Thanks, Chris