[ale] UART Debugging headache w/ embedded Linux SBC

[johnmills at speakeasy.net (John Mills)]

ALErs (particularly embedded-processor wonks) -

I have an ARM/linux single-board computer that experiences irregular but
fairly frequent (~1s. to 3:45hr.) lockups. It appears that an off-board
16550A UART has requested an interrupt that was not successfully reset by
the (generic) kernel driver. It may send 200 packets fine, then lock -
effectively freezing the board.

I see chip-selection activity but the ISR line is solidly asserted.

Any suggestions on how to debug this @#$%!!???

TIA.

 - Mills