[Solved] anything in base that automatically reboots the system?

[curaga]

HDD health can be checked with "smartctl -a /dev/sda" (from smartmontools.tcz), but that's not likely to cause a reboot.

[CNK]

I have two wireless USB adapters connected to the laptop (wlan1 and wlan2).

If you used them with both laptops then it's also (slightly) possible that one is failing and that's exposing a bug in the wireless driver which causes a kernel crash.

[tacpilot]

A kernel panic would reboot in one minute by default (configurable)

Since rebooting is not configured for any power related settings, and other hardware
have been removed from the equation, the only thing seems able to force a reboot
is the kernel panic setting.

Going on the assumption that a (failing drive / data corruption) is causing kernel panic.

If you used them with both laptops then it's also (slightly) possible that one is failing and that's exposing a bug in the wireless driver which causes a kernel crash.

Following previous suggestion to ensure are running solely from RAM, would
help expose such issues if reboots continue.

Could go as far as to set the reboot time for kernel panic to extreme high number
so as to visually verify that a panic is what's happening before it gets a chance to reboot.

[GNUser]

smartmontools shows nothing concerning and total bytes written = 0.172373 TiB (well below the drive's expected useful life).

No reboots for over 12 hours, which is a record since this issue came to my attention The only difference between current setup and the previous iteration (which did have an unexpected reboot) is the TCL downgrade to version 12.

I'm chalking this up to a linux kernel regression between 5.10.3 and 5.15.10 that affects this specific use case (wireless router with multiple wireless interfaces). But with the other small changes between TCL versions it's hard to definitively exclude some other possibility.

Topic may be marked as solved. If I have bad news (another unexpected reboot) or good news (a week or more without unexpected reboots), I'll let you all know.

You are a sharp and generous bunch. Thank you very much for all your help.

P.S. CNK, in one of the several iterations of my setup I did change the wireless USB adapters to different ones with identical chipset (Ralink RT5370) and the issue recurred. So it was not a hardware problem with the adapters.

[GNUser]

Downgrading to TCL12 x86_64 seems to have done the trick: No more unexpected reboots for 72 hours and counting! Maybe the new kernel version in TCL13 x86_64 had a regression that affected this particular use case.

Topic may be marked as solved

P.S. The laptop has been running without a battery at all. So my hypothesis that a missing or broken battery may have been responsible for the reboots seems to have been disproven.

[Rich]

Hi GNUser

... Maybe the new kernel version in TCL13 x86_64 had a regression that affected this particular use case. ...

Here are 2 other possible causes:
1. One or more extensions were updated.
2. One or more extensions were not updated but should have been.

Topic marked as solved. 

[GNUser]

Hi, Rich. If I were to do any more testing now and cause additional router reboots at bad times, wife would kill me.

To exclude your hypothesis #2, when TCL14 comes out I'll submit new versions of the two workhorse extensions (hostapd.tcz and dnsmasq.tcz) and will test it out.

[Rich]

Hi GNUser
It was merely an observation, not a suggestion to do more testing.

[GNUser]

Hi, Rich. I know--that was my bad conscience putting me on the defensive because I am lazy and didn't want to do what I knew needed to be done.

I went ahead and compiled latest hostapd and dnsmasq on TCL13 x86_64 and am testing everything on my router. Worst that can happen is that I have one more unexpected reboot, I have to downgrade to TCL12 on the router (again), and wife makes me sleep on the sofa for one night

Juanito, I will submit refreshed hostapd and dnsmasq extensions for TCL13 x86_64 now.

[Rich]

Hi GNUser

... and didn't want to do what I knew needed to be done. ...

Once again, It didn't need to get done. You solved the issue in a way that met your needs, and
there's nothing wrong with that.

Allow me to play the role of PITA:

... Maybe the new kernel version in TCL13 x86_64 had a regression that affected this particular use case. ...

Here are 2 other possible causes:
1. One or more extensions were updated.
2. One or more extensions were not updated but should have been.

3. An existing bug was made more visible by the new kernel version. The issue will recur in the older
   kernel, but not for 53 days, You will not make the connection because you will have forgotten
   about this thread by then. 

[GNUser]

Good news: I've had no unexpected reboots while running the router with TCL13.1 Pure64 and the updated hostapd.tcz and dnsmasq.tcz extensions. It's been 48 hours and counting.

I'm glad I pressed on. Refreshing the two extensions seems like a more proper fix (and more likely to help the community) than just downgrading to TCL12.

Thank you all, especially Rich, for your help in coming up with the list of possible root causes. This was a tough one!

[Rich]

Hi GNUser
Congratulations on your success and avoiding nights on the couch.