linux-image-4.15.0-44-generic on Thinkpad T480s with docking station - unresponsive black screen

[Jonas Dahlbaek]

Upon upgrading linux-image-generic and linux-header-generic from version 4.15.0.43.45 to version 4.15.0.44.46, my Lenovo Thinkpad T480s no longer works when plugged into its docking station. Symptoms seem similar to those described in https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1811860, but downgrading firmware has no effect.

What I expected to happen: When plugging my laptop into the docking station, the touchpad, keyboard and mouse are responsive, and internal and external displays work.

What happened: When plugging my laptop into the docking station, the touchpad, keyboard and mouse where unresponsive. External display was black and internal display was frozen. Unplugging the laptop did not have any effect. Hard reboot by holding the power button was required.

After booting into 4.15.0-43-generic and removing linux-image-4.15.0-44-generic and linux-headers-4.15.0-44-generic, the problem disappears.

Should anyone else wish to follow the same steps until the problem is resolved, make sure you do not try to remove the kernel that you are currently on. That is, do not run the command

sudo apt-get remove linux-image-4.15.0-44-generic linux-headers-4.15.0-44-generic

unless you booted into an older kernel.

Addition info
-------------

$ lsb_release -rd
Description: Ubuntu 18.04.1 LTS
Release: 18.04

$ apt-cache policy linux-image-generic:
linux-image-generic:
  Installed: (none)
  Candidate: 4.15.0.44.46
  Version table:
     4.15.0.44.46 500
        500 https://mirror.one.com/ubuntu bionic-security/main amd64 Packages
        500 https://mirror.one.com/ubuntu bionic-updates/main amd64 Packages
     4.15.0.20.23 500
        500 https://mirror.one.com/ubuntu bionic/main amd64 Packages

log entry from /var/log/apt/history.log showing installation of packages that caused the problem:

Start-Date: 2019-01-30 09:54:45
Commandline: aptdaemon role='role-commit-packages' sender=':1.113'
Install: linux-image-4.15.0-44-generic:amd64 (4.15.0-44.47, automatic), linux-headers-4.15.0-44:amd64 (4.15.0-44.47, automatic), linux-headers-4.15.0-44-generic:amd64 (4.15.0-44.47, automatic), linux-modules-extra-4.15.0-44-generic:amd64 (4.15.0-44.47, automatic), linux-modules-4.15.0-44-generic:amd64 (4.15.0-44.47, automatic)
Upgrade: irqbalance:amd64 (1.3.0-0.1, 1.3.0-0.1ubuntu0.18.04.1), linux-headers-generic:amd64 (4.15.0.43.45, 4.15.0.44.46), linux-libc-dev:amd64 (4.15.0-43.46, 4.15.0-44.47), linux-image-generic:amd64 (4.15.0.43.45, 4.15.0.44.46), libasound2-data:amd64 (1.1.3-5ubuntu0.1, 1.1.3-5ubuntu0.2), linux-signed-generic:amd64 (4.15.0.43.45, 4.15.0.44.46), libasound2:amd64 (1.1.3-5ubuntu0.1, 1.1.3-5ubuntu0.2), linux-generic:amd64 (4.15.0.43.45, 4.15.0.44.46)
End-Date: 2019-01-30 09:55:18

log entry from /var/log/apt/history.log showing removal of packages that fixed the problem:

Start-Date: 2019-01-30 14:54:33
Commandline: apt-get remove linux-image-4.15.0-44-generic linux-headers-4.15.0-44-generic
Requested-By: dahlbaek (1000)
Remove: linux-image-4.15.0-44-generic:amd64 (4.15.0-44.47)
End-Date: 2019-01-30 14:54:36

[Seth Forshee (sforshee)]

Since it works in 4.15.0-43 but not in 4.15.0-44, this appears to be a kernel regression and not a firmware problem. Reassigning to the linux package.

[Jonas Dahlbaek (dahlbaek)]

Thank you. Perhaps I should also note that everything worked as expected if plugged directly into the laptop, without using the docking station.

[Seth Forshee (sforshee)]

Looks like this is the same as bug 1813663.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Rojin Kianian (mcrojin)]

I had the same issue on Lenovo Thinkpad X1 Carbon (6th generation), also resolved by downgrading to the old kernel version.

The monitors work with the docking station until the lock screen causes the computer to suspend. After that it's locked with black screens and unresponsive until I do a hard reboot using the power button.

[Lars Skjærlund (larsskj)]

This bug affects me as well: Lenovo X1 Carbon 6th generation.

[Jon Ball (jonathon-ball)]

This bug is affecting several of my coworkers!!

[Jonas Dahlbaek (dahlbaek)]

I can verify that updating to 4.15.0.45.47 fixed this problem for me.