[SOLVED] System crash/freeze when disconnecting docking station

seth · 2024-09-01 11:56:07

You can use the Same kernel for both.

Utini · 2024-09-02 05:17:16

Hi @seth,

in that case I am still missing something. I will try to explain step-by-step:

1. install kexec-tools
2. set crashkernel=256 in systemd-boot options for linux kernel
3. reboot
4. run the command "kexec -p /boot/vmlinuz-linux --initrd=/boot/initramfs-linux.img --append="irqpoll nr_cpus=1 reset_devices"
5. Force the crash
6. Force reboot by long pressing the power button (ctrl+alt+del doesn't work)
7. Laptop will reboot as normal
8. Unlock LUKS/LVM and boot up KDE 
9. makedumpfile -z -d 31 /proc/vmcore /root/vmcore.crashdump_compressed
10. Provide you the crash file or analyze it myself

Correct?

Last edited by Utini (2024-09-02 06:42:54)

seth · 2024-09-02 08:08:00

5. Force the crash
6. Force reboot by long pressing the power button (ctrl+alt+del doesn't work)
7. Laptop will reboot as normal

No, force the crash, the other kernel will take over, you get a memory dump of the crashed kernel that you can then inspect w/ crash.
Do not reboot before you've secured the coredump or it'll be lost.

You can use kdumpst to automatize this, but I've never used it, so we just assume it'll do the right thing

Utini · 2024-09-02 09:56:40

Ahh I guess I was just not patient enough!

So I forced the crash, waited 2-3 mins and then the system was usable again.
I have no dump but I now have a bigger journalctl file.

"/proc/vmcore/" does not exist. So it seems like no dump was created?

Here is the journalctl though, which contains more valuable information?
Link: https://files.bestmail.ws/Arch/journal0209_3.txt

I didn't reboot the system so far - so let me know if I should check/export anything else

Last edited by Utini (2024-09-02 09:57:37)

seth · 2024-09-02 11:26:10

There's no kernel error in that log, but xfreerdp3 crashes.
Since it 26k lines covering 5h, when about did the crash occur?
~11:45 ?

I currently doubt you're actually facing a kernel panic here.
Do you have the same problem w/ a plasma/X11 session?

Utini · 2024-09-02 12:22:52

Oh sorry - forgot to mention: The crash happened only a few minutes before creating the log. 11:35 or 11:45 seems to be the time (ethernet connection disconnected).

I didn't try X11 yet but I can try tomorrow.

seth · 2024-09-02 14:27:32

You end up w/ no screen

Sep 02 11:45:28 S2000 konsole[22684]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
Sep 02 11:45:28 S2000 baloorunner[2405]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
Sep 02 11:45:28 S2000 keepassxc[7118]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash

at least xwayland doesn't like that

Sep 02 11:45:28 S2000 kwin_wayland_wrapper[1696]: XWAYLAND: mode -1x-1 is not available

and then all hell breaks lose.

I guess the eDP is deactivated while running on the dock (and using an external monitor)?
Try to explicitly enable it first.

Utini · 2024-09-03 08:11:12

Yes the eDP (laptop display) was disabled. I have now enabled it and the docking disconnect is a lot more fluid now. Also no crashes/freezes so far.
But that means wasting energy on the laptop display since it is of no use atm.

@Edit: The following might be a different problem/bug. It should be possible to get 3 screens (2x external + 1x internal) via USB C.
Also with USB-C (USB 3.2) it seems like I can't output three different displays in total, meaning the laptop display will always be mirrored.
The USB4 port does allow three individual displays but it gets unnecessary hot then. Its a bug with the Thinkpad T14s G3 AMD where the USB4 port gets so hot that even the CPU temps rise.

Last edited by Utini (2024-09-03 08:15:15)

seth · 2024-09-03 13:08:49

But that means wasting energy on the laptop display since it is of no use atm.

You only need to make sure to enable the eDP before you undock the device.
What happens is that you've an external monitor, then you undock, have no external monitor, have no output at all (most likely kscreen resizes the otput to 0x0) and a bunch clients lose it over that.

An alternative approach would be to disable the kscreen daemon and ideally of course the undocking even would implicitly enable the eDP *before* the system responds to the output loss (you could try a udev rule or fox X11, if the problem manifests there at all, x-on-resize)

Also with USB-C (USB 3.2) it seems like I can't output three different displays in total, meaning the laptop display will always be mirrored.

=> X11 session and "xrandr -q" and xorg log for that setup (the data is pointless in the context of wayland, you can check kscreen-doctor on this, but idk how much that is maybe impacted by the wayland compositor)

Utini · 2024-09-04 05:16:27

Thanks for your debugging help and thanks for the hint to kscreen-doctor.

I have now managed to use the three screen all together at their maximum capabilities:
eDP at FHD 60Hz
Screen 1 at FHD 75Hz
Screen 2 at FHD 60Hz

I will see if I can reduce the brightness of my eDP automatically when switching to this setup and then use that eDP for various different side tasks that I have yet to find and define ;-P
I am going to set this to solved but I wonder if this issue might hunt other people as well and if some kind of a fallback solution should be provided?
E.g. such a udev rule by default or atleast mentioning it somewhere in the wiki?

seth · 2024-09-04 06:25:10

https://wiki.archlinux.org/title/ThinkPad_docks but technically this isn't dock related.
The main bug that generally needs to be addressed / worked around is that (wayland?) clients are unable to handle a headless situation which is maybe such a general issue that one might expect a screen managing daemon to handle and catch it globally by either being more smarterer™ and enabling a remaining one or adding a fake VGA output.

Arch Linux

#26 2024-09-01 11:56:07

Re: [SOLVED] System crash/freeze when disconnecting docking station

#27 2024-09-02 05:17:16

Re: [SOLVED] System crash/freeze when disconnecting docking station

#28 2024-09-02 08:08:00

Re: [SOLVED] System crash/freeze when disconnecting docking station

#29 2024-09-02 09:56:40

Re: [SOLVED] System crash/freeze when disconnecting docking station

#30 2024-09-02 11:26:10

Re: [SOLVED] System crash/freeze when disconnecting docking station

#31 2024-09-02 12:22:52

Re: [SOLVED] System crash/freeze when disconnecting docking station

#32 2024-09-02 14:27:32

Re: [SOLVED] System crash/freeze when disconnecting docking station

#33 2024-09-03 08:11:12

Re: [SOLVED] System crash/freeze when disconnecting docking station

#34 2024-09-03 13:08:49

Re: [SOLVED] System crash/freeze when disconnecting docking station

#35 2024-09-04 05:16:27

Re: [SOLVED] System crash/freeze when disconnecting docking station

#36 2024-09-04 06:25:10

Re: [SOLVED] System crash/freeze when disconnecting docking station

Board footer