Good news: s390
My s390 runs 2.4.21-pre3 with RH patches, which is nice. I'll get s390x going and send rmap updates to Riel.
Bad news: USB
IBM report that my fix for the initial USB caps lock does not work for them. This is entirely unexpected. The bug was obvious, and the fix was obvious, I tested the result, and Vojtech approved it. Userland is not involved. Something is very fishy here...