RE: how can we tell system to shutdown on a power fail, using systemd and apcid

I think i see something interesting
they did some changes to the dt for the pmic
https://patchwork.kernel.org/patch/9771235/
some of the comments deal with interrupts
seems the one that is missing or not handled is "AC"
or something needs to be written to handle "AC" now
I read something about breaking out the power button interrupt
in some other verbage today
as with the old kernel PB and AC fail did the same thing
but to get AC fail to trigger a power off you needed apcid
or at least it did not shut down till you installed acpid

This is deeply buried in kernel land. might need to monitor
a PG signal from the power supply and act on it with APCID
till this is resolved

At least if you do that you can set an interrupt with a powerfail gpio
and write an APCID handler