Four of my five Raspberry Pi boot flawlessly upon
sudo reboot; one fails. This RPi, but none of the others, has a Hifiberry Amp2 mounted on the GPIO header.
I suspect for the below reasons that the failure to reboot is due to the Hifiberry Amp2 and the way this RPi is powered; although the Hifiberry manufacturer does not think so.
- To recover, I need to unplug the power supply from the mains, wait a bit then reconnect to power.
- The RPi gets its power from the Hifiberry Amp2 (that is powered by an 18 V power supply), i.e., power flows in through the GPIO 5V pins which is the reverse of the usual direction.
- The log of each failed reboot refers as last or second but last entry to the Hifiberry:
pi@knoutberry:~ $ uname -a Linux knoutberry 5.4.79-v7+ #1373 SMP Mon Nov 23 13:22:33 GMT 2020 armv7l GNU/Linux pi@knoutberry:~ $ sudo journalctl --boot=-1 --dmesg --lines=3 -- Journal begins at Tue 2022-11-29 23:45:56 UTC, ends at Mon 2023-02-27 06:52:45 UTC. -- Feb 26 17:50:14 knoutberry kernel: rc rc0: two consecutive events of type space Feb 26 17:50:14 knoutberry kernel: snd-rpi-hifiberry-dacplus soc:sound: pcm512x-hifi <-> 3f203000.i2s mapping ok Feb 26 17:50:14 knoutberry kernel: proc: Bad value for 'hidepid'
On the other hand, HifiBerry Amp2 is a common device and surely not preventing reboots for everyone. And snd-rpi-hifiberry-dacplus soc:sound: pcm512x-hifi <-> 3f203000.i2s mapping ok is a normal status, neither an error nor a warning. BTW, the very last entry Bad value for 'hidepid' is also present in boots that work, i.e., after reconnecting to power, and may be ignored.
Any idea how I could further investigate? Thanks for suggestions.