Ubuntu 20.04 with newest kernel 4.9 reboots

Dear supporters,

I have a problem vim3. I use ubuntu 20.04, i upgrade it (also I install xfce4 and lightdm).

My khadas vim3(i tested on 2 pcs of boards). I connect khadas to power supply 12v/5a.

Khadas reboot every few minutes after boot. Even i don’t need login to xfce.

I attach the screen when it reboots.

How can solve or diagnose the problem?

if you can try to track how much time it takes for the reboot to happen,
I think something might be shorting the xpwr pads on the back perhaps,
check for any hardware complications before checking the software part,

also share your linux image number (eg. v200530, etc. )

Dear Electr1:

I used "VIM3_Ubuntu-minimal-focal_Linux-4.9_arm64_EMMC_V0.9.6-201117.raw.img.xz image. I Installed it by krescue. After installed (as is described - How To Upgrade The System To Latest Version | Khadas Documentation)

I recorded video with loop. After login to linux I don’t touch keyboard. (Without login also it will reboots): https://youtu.be/m1zUdvBlh_8

BTW I need OS with Linux 4.9 becouse I have to use khadas camera…

that is very bizzare, I don’t have a Edge-v at hand to test the image,

I would ask about the power supply, but as you have stated its rated 12v/5A,

can you try disconnecting the camera, a different display or some other hardware configuration ?

I actually disconnect all. (same result)

I discovered that, watchdog daemon trigger reboots (I dissable watchdog service). Do you know why it trigger?

ah… watchdog,
that explains it,

watchdog is basically like what the name insists, its a watchdog timer that monitors the CPU basically will reset the computer after a set period of time, in case where there is a software glitch that hangs the system…

mostly used in embedded systems to monitor bugs or hangs that will otherwise render the system un-functionable when there is a system hang, as its better to reboot and try to get out of the bug, than rather let the CPU be idle and stuck…

usually the watchdog gets “kicked” and resets the timer, but since such a case it not preset the watchdog isn’t kicked in time, and your system is getting rebooted as seen…

you can disable it in the system, and the documentation is there:

just run:

sudo systemctl disable watchdog

it should solve the issue, I hope this solves the problem :slightly_smiling_face:
kudo for discovering it…

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I found out the trhead about watchdog in vim3 - Internal HW Watchdog? - #14 by odibox

I try it latter.

I disabled watchdog and i see that it doesn’t reboot.

Thank you.

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