Power-On button does not always work

[tllim]

I was investigating why the power button does not always work to turn the Pine back on (shuts down after 5 seconds) after a shutdown with no power cycle.

It seems to work reliably with a battery connected though. After comparing the boot logs I think I found the issue, but need some input on how to fix this,
probably in the ATF or by making sure the AXP803 is in the right state after a shutdown with power-off.

Boot log differences: https://www.diffchecker.com/ZVbSo0ap (Left column is cold boot from power cycle, Right column is button triggered boot after a previous shutdown)

1.) On a cold boot the AXP detects correctly that there is no battery ( see lines 16, 38 in the diff )

no battery, limit to dc  vs. normal dc exist, limit to dc

2.) A bit later in the startup this leads to (see line 117ff)

no battery exist vs. PowerBus = 2(0: not exist 1:vBus 2:acBus 3:vBus&acBus) Battery Voltage=0, Ratio=0 key trigger battery low power and vol with dc or ac, should charge longer

3.) And in the right case, the system gets switched off (see line 129)

[ 5.742]power off

So what basically happens is, that on a cold boot the AXP properly detects that there is no battery and so no issues with the battery voltage... after a shutdown without a power-cycle the AXP seems to come back in a state where it has a battery detected (even if there is none) and the low battery voltage / charge level triggers a power-off....

I have pass your info to Allwinner engineer and lets check whether they can provide a good solution.