Automatic powering on and not staying powered off

[dsimic]

Hello,

This thread is a fork from another thread, as requested by the OP.  First, here's a sum-up of what's been already discussed:

When the phone is connected to the official dock, and a charger is plugged into the dock, shutting down the operating system causes the phone to power off and, unexpectedly, power back on immediately.  I've tested it more than a few times, and it always (mis)behaves like that.

Another side effect is that the device will not stay off with DCIN powered - no charging while switched off, it keeps booting up again :-(

This is pretty much the same behavior as with the official dock connected to the phone, which I've described earlier in this post.

After reviewing the relevant part of the available documentation for AXP803 (i.e. the PMIC), it's clear why this happens with 5 V applied to the DCIN pogo pin.  Basically, the PMIC detects the presence of valid input power voltage, which is satisfied in this case, and automatically begins the power-on procedure.  However, this doesn't explain the same behavior with the official dock plugged into the phone.

Phone -> USB C to A cable -> old "dumb" power brick -> AC wall outlet: Connecting the first time causes the phone to power on. But I can power the phone off from software, and then it stays "off".

Phone -> convergence dock -> USB C to a cable -> old "dumb" power brick -> AC wall outlet: Connecting the first time causes the phone to power on. After powering off the phone from software, the phone powers back on; won't stay "off".

anx7688 doesn't do anything unless the pinephone is powered on, so there's some fun to be had when charging via USB-PD chargers when the phone is off.

Maybe that's related to this, i.e., maybe the phone powers on by design, so that USB-PD can be negotiated if applicable.

I also remember reading that, for similar reasons, while charging, Android phones tend to be booted up. At least into the bootloader, and then the bootloader maybe knows to enter a different "charging indication" mode or to "stop here" until X or Y event happens.

Anyways, my point is that either of the two conflicting observations can happen, depending on which hardware you connect. If you want to reproduce my "off" test cases, try using a "dumb" brick without USB-PD.