Kernel soft lockup after resume

[Michael Kuefner]

Sometimes the kernel hangs after resuming from suspend.
It might be a problem when suspending, while the DELL thunderbolt dock is connected.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: linux-image-5.13.0-25-generic 5.13.0-25.26
ProcVersionSignature: Ubuntu 5.13.0-25.26-generic 5.13.19
Uname: Linux 5.13.0-25-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: minni 5443 F.... pulseaudio
 /dev/snd/pcmC0D0c: minni 5443 F...m pulseaudio
 /dev/snd/pcmC0D0p: minni 5443 F...m pulseaudio
 /dev/snd/timer: minni 5443 f.... pulseaudio
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Thu Jan 13 15:53:19 2022
InstallationDate: Installed on 2020-12-19 (389 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
MachineType: Dell Inc. XPS 15 9500
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.13.0-25-generic root=/dev/mapper/vgubuntu-root ro quiet splash acpi_osi=Linux vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-5.13.0-25-generic N/A
 linux-backports-modules-5.13.0-25-generic N/A
 linux-firmware 1.201.3
SourcePackage: linux
UpgradeStatus: Upgraded to impish on 2021-10-17 (88 days ago)
dmi.bios.date: 05/26/2021
dmi.bios.release: 1.8
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.8.1
dmi.board.name: 05XYW7
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.8.1:bd05/26/2021:br1.8:svnDellInc.:pnXPS159500:pvr:rvnDellInc.:rn05XYW7:rvrA00:cvnDellInc.:ct10:cvr:sku097D:
dmi.product.family: XPS
dmi.product.name: XPS 15 9500
dmi.product.sku: 097D
dmi.sys.vendor: Dell Inc.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Thomas (t.c)]

Have a look at this webpage..

https://01.org/blogs/rzhang/2015/best-practice-debug-linux-suspend/hibernate-issues

In short:

1. edit your /etc/default/grub
a. make a COPY of the line GRUB_CMDLINE_LINUX_DEFAULT and modify like this:

GRUB_CMDLINE_LINUX_DEFAULT="initcall_debug no_console_suspend ignore_loglevel"
#GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

2. run 'sudo update-grub' to reflect the changes
3. reboot your pc
4. put your pc into STR, eg with 'echo mem | sudo tee /sys/power/state'

5. when your PC is suspended, wake it up and report back what you find.

[Michael Kuefner (herrminni)]

Hi Thomas,

thank you for the help to gather more information.
I added "initcall_debug" in grub and tested the suspend / cpu-lockup problem after a rebooting into the new grub config.

I tried it different times, and can say, that the connected Thunderbolt dock was not the problem, as the cpu-lockup also happens, when the laptop was not connected to anything.

It is not happening on each suspend, but after some rounds of suspend+resume I can see the problem.

In the attachment is the kern.log with two incidents, the last one took quite a while (8000s).

If you have any other idea or have things I can test, I am happy to help!

Best regards,
Michael