Hi Nick,

Thanks for tracking this down. It's a fix for my breakage

a7cba02deced ("powerpc: allow soft-NMI watchdog to cover timer
interrupts with large decrementers")

Taking another look... what I had expected here is the timer subsystem
would have stopped the decrementer device after it processed the timer
and found nothing left. And we should have set DEC to max at that
time.

The above patch was really intended to only cover the timer interrupt
itself locking up. I wonder if we need to add

    .set_state_oneshot_stopped = decrementer_shutdown

In our decremementer clockevent device?

Thanks Nick, that looks much nicer, and passes my tests.

Anton