I'd suggest enabling dynamic debug for the Thunderbolt driver and possibly the pcie hotplug driver.
In /etc/default/grub, add these two options inside the quotes after GRUB_CMDLINE_LINUX: thunderbolt.dyndbg=+pmf pciehp.dyndbg=+pmf Then update the Grub config and reboot: sudo update-grub It will likely cause a lot more log noise, so you'll want to keep an eye on the disk usage in /var/log/journal and look up how to rotate and flush the systemd logs if it gets big. On my AMD machine, I've been having rather inconsistent behavior with Thunderbolt as well. Sometimes DisplayPort tunneling is randomly unavailable, and sometimes the dock fails to link up at all. When Thunderbolt goes dead, it can be helpful to unload and then reload the thunderbolt driver: sudo modprobe -r thunderbolt; sleep 15; sudo modprobe thunderbolt With my machine being AMD, my issues could have a wildly different cause, but perhaps the expanded logs with dyndbg could still give developers some clues. To get a full log since boot, you can do something like this: sudo journalctl -b -t kernel > kernel-journal.log ** Attachment added: "thunderbolt-fail.log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2139079/+attachment/5947359/+files/thunderbolt-fail.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2139079 Title: Thunderbolt regression: PCIe tunnel activation fails with tb_path_activate WARN on 6.17.0-8 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2139079/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
