Where are the logs ? (Random daily reboots)

Brand : Xiaomi
Model : Mi A1
/e/ version : 1.19.1-s (latest available)
Issue : multiple daily random reboot

Hello,

I installed this /e/ version and everything was fine.
I have no idea why but now, the phone reboots a multiple time per day (hard reboot).
Can you tell me where can I look (logs, files, settings) in order to obtain some information about this issue ?
A logcat would help a lot but as reboot occurs randomly I can’t keep it plugged on the PC the whole day.
On Linux I am able to find when these things occurs (kernel message, logs…) but on Android I have no idea where these logs are.

Thank you a lot.

you could check LogFox for a permanent log option that you fetch after the reboot

Thank you for the suggestion.
I tried to perform a log but it doesn’t help as LogFox close when the phone reboot and at this moment I lose the whole log.

After few search, I found something that LogFox or similar app are not able to catch.

I found something in “console-ramoops-0” file (/sys/fs/PSTORE/)
Ramoops is a panic logger and logs thing when the system crash.

HERE is the log.
CRTL + F and search “Fatal error”
It appear that this crash and the reboot comes from the modem : Fatal error on the modem.
I take the train every day and there are some areas without network. The phone can easily reboot in this kind of area.
Also it occurs something when I turn on/off the flight/airplane mode.

I can understand that this devices is not the youngest one. Is has more that 5 years.
I just do not understand why this issue appears now. Everything was ok in the past.

(wasn’t aware some builds have now pstore enabled by default? hu)

to surface that line completely:

[16063.799993] Fatal error on the modem.
[16063.800000] modem subsystem failure reason: EXCEPTION:0:CAUSE=3;ELR=d0960fe4;FP=8b195478;TID=ea;TASK=rrc_0.
[16063.902891] Kernel panic - not syncing: subsys-restart: Resetting the SoC - modem crashed.

seems prior there’s some putting-to-sleep going on?

there’s something similar at the bottom at https://gitlab.com/LineageOS/issues/android/-/issues/1503 that leads to a lineage patch for subsys-restart ignoring RESET_SOC. Your device kernel carries those original lines. You’d need to read into patch discussion if it’s a good idea. Worst case modem doesn’t come back and you’ll need to reboot manually to reset it.

Hello,

thank you for the links and explanation.

I have been delving deeper into this topic and for some unknown reason, my phone has stopped rebooting. It has not rebooted since I posted my last message.The issue appeared randomly and disappeared in the same way.

Could something on the carrier side be causing this issue?

Recently, I received a message from my carrier informing me that they had been acquired by another carrier. Although I have not received a new SIM card, I was told to reboot my phone in order to get new APN settings.

I hope I don’t run into this again.

Thank you for your help.