Public bug reported:
After upgrading the Linux kernel to version 6.8.0-51 on Ubuntu 22.04,
the external monitor connected via DisplayPort through a docking station
over USB-C stopped functioning. The monitor is no longer detected by the
system, and no output is displayed. However, when connecting the same
monitor via HDMI, it works as expected.
Steps to Reproduce:
Update the kernel to version 6.8.0-51 using unattended-upgrades or manual
installation.
Connect a docking station to the laptop via USB-C.
Connect an external monitor to the docking station via DisplayPort.
Check if the monitor is detected in the display settings or xrandr.
Expected Behavior:
The external monitor connected via the docking station using DisplayPort should
be detected and function correctly, as it did in the previous kernel version
6.8.0-50.
Observed Behavior:
The monitor connected via DisplayPort through the docking station is not
detected, and no output is displayed.
Connecting the monitor via HDMI directly or through the docking station works
as expected.
Additional Information:
Kernel version: 6.8.0-51 (affected), 6.8.0-50 (working).
Ubuntu version: Ubuntu 22.04.5 LTS.
Docking Station: Lenovo ThinkPad USB-C Dock, Type 40A9
Connection setup: Laptop → USB-C → Docking Station → DisplayPort → Monitor.
Workaround:
Reverting to kernel version 6.8.0-50 resolves the issue, and the monitor
functions as expected when connected via DisplayPort through the docking
station.
ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: linux-image-6.8.0-51-generic (not installed)
ProcVersionSignature: Ubuntu 6.8.0-50.51~22.04.1-generic 6.8.12
Uname: Linux 6.8.0-50-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.6
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Jan 14 08:51:54 2025
InstallationDate: Installed on 2024-05-13 (246 days ago)
InstallationMedia: Ubuntu 22.04.3 LTS "Jammy Jellyfish" - Release amd64
(20230807.2)
SourcePackage: linux-signed-hwe-6.8
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: linux-signed-hwe-6.8 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug jammy wayland-session
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2094733
Title:
External monitor not working after kernel update to 6.8.0-51 on Ubuntu
22.04 (DisplayPort over USB-C)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-6.8/+bug/2094733/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
