ubuntu 18.04 linux 4.15.0-44 kernel exception with ThunderBolt display

[Gene Olson]

This problem appeared on the first boot Linux 4.15.0-44, and was not present in previous kernels, including 4.15.0-43. The problem occurs every time with 4.15.0-44. Since the problem occurred, 4.15.0-43 continues to work w/o issues. The log should show multiple boots with both kernels, both Xorg and Wayland.

The problem occurs wheen connecting a TB-16 dock-connected external display, or when plugging in a TB-16 dock-connected external display during an X session. The symptoms are different with Xorg and Wayland, but both cause kernel exceptions. With Xorg the system freezes up, but will still ping. With Wayland the display goes black, but userland is still accessible. With Xorg the system is gone before the Login screen appears. With Wayland the login screen is okay, but the problem occurs immediately after a successful login. The system runs normally with both Xorg and Wayland so long as the external display is not connected.

The problem does not occur if the display is plugged in through a USBc (non-ThunderBolt) port.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-44-generic 4.15.0-44.47
ProcVersionSignature: Ubuntu 4.15.0-44.47-generic 4.15.18
Uname: Linux 4.15.0-44-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: gene 1982 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Wed Jan 30 16:49:20 2019
HibernationDevice: RESUME=UUID=d15ecb23-8691-42a1-9909-a56f934b536c
InstallationDate: Installed on 2018-11-19 (72 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
MachineType: Dell Inc. XPS 15 9570
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-44-generic root=UUID=a73e2d3e-5ce3-4130-917d-d116c1316153 ro net.ifnames=0 mem_sleep_default=deep
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-44-generic N/A
 linux-backports-modules-4.15.0-44-generic N/A
 linux-firmware 1.173.3
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/25/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.7.0
dmi.board.name: 02MJVY
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.7.0:bd12/25/2018:svnDellInc.:pnXPS159570:pvr:rvnDellInc.:rn02MJVY:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 15 9570
dmi.sys.vendor: Dell Inc.

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

This change was made by a bot.