Can you test the 6.8.0-53 from proposed updates? After upgrading the laptop I described my problem with, the problem seems fixed for me.
I've repeatedly booted to 51, 52 and 53, and currently it looks to me the problem I described actually did exist on both 51 and 52, and gone with 53. So it definitely seems like a regression, but happened already earlier. This is also logical because of the small size of the 52 kernel differences. It is possible my bug is a different one from this, so I filed LP: #2097251. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in 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) Status in linux package in Ubuntu: New Status in linux-hwe-6.8 package in Ubuntu: New Status in linux-signed-hwe-6.8 package in Ubuntu: Confirmed Bug description: 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) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2094733/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
