All,

ISA irq handling appears to be somewhat broken in -current (on a Multia,
firmware 3.4.3).

Serial console works until the machine goes multi-user (but emits a lot of
stray interrupt messages for irq 4), then abruptly dies midway through the
adding-swap message (or root-shell message in single-user mode).

My thinking was that the serial interrupt handler wasn't being called, but
this does not appear to be the case -- comintr() is called and fails at the
ISSET(iir, IIR_NOPEND) call.

I'm confused.  Can anyone give me pointers on how to proceed?

-- Chris