In this article, we will delve into the process of troubleshooting and resolving DisplayPort issues with a ThinkPad USB-C Dock on Ubuntu 18.04. This guide is meant to assist users who have encountered issues with their DisplayPorts not being detected on a ThinkPad T480s when using a ThinkPad USB-C dock.
To fix DisplayPort issues with a ThinkPad USB-C Dock on Ubuntu 18.04, try switching to the default GNOME display manager using the command "sudo dpkg-reconfigure gdm3". If that doesn’t work, create a configuration file named "20-displaylink.conf" with specific settings. Power cycling the dock and updating its firmware are also potential solutions. However, it’s important to note that there isn’t a definitive solution, and some issues may require further assistance from Lenovo’s customer support.
Before diving into the troubleshooting process, it’s important to ensure that you have tried different DisplayPort cables and ports in the dock, as well as different displays. This is a basic troubleshooting step that can help rule out any hardware-related issues.
Switching to the Default GNOME Display Manager
The first step in the troubleshooting process is to switch to the default GNOME display manager. This is a relatively straightforward process that can be done by running the following command in the terminal:
sudo dpkg-reconfigure gdm3
This command reconfigures the GNOME Display Manager (gdm3) and sets it as the default display manager. It’s worth noting that this step alone may resolve the issue.
Creating a Configuration File
If switching to the default GNOME display manager doesn’t resolve the issue, the next step is to create a configuration file named “20-displaylink.conf” under the “/usr/share/X11/xorg.conf.d/” directory. This file will help in using the “modesetting” driver and disabling page flipping, which may be necessary for proper functionality.
To create this file, use the following command:
sudo nano /usr/share/X11/xorg.conf.d/20-displaylink.conf
This command opens the nano text editor with superuser (sudo) permissions and creates a new file named “20-displaylink.conf” in the specified directory.
In this file, paste the following content:
Option "PageFlip" "false"
This configuration sets the driver to “modesetting” and disables page flipping. Once you’ve pasted this content, save the file and exit the text editor.
Power Cycling the Dock
If the issue persists after creating the configuration file, it may be worth power cycling the dock. This can be done by restarting your computer or unplugging the dock from the power source, waiting a few seconds, and then plugging it back in.
Updating the Dock’s Firmware
As a last resort, you can try performing a firmware update on the dock. This process varies depending on the specific model of your dock, so it’s recommended to refer to the manufacturer’s instructions or visit the official Lenovo support website.
While there isn’t a definitive solution to the issue of DisplayPorts not being detected on a ThinkPad T480s running Ubuntu 18.04 with a ThinkPad USB-C dock, the troubleshooting steps outlined in this article may help resolve the issue. It’s worth noting that in some cases, the issue resolved itself after a few restarts and trying different connections. If you continue to experience issues, consider reaching out to Lenovo’s customer support for further assistance.
This guide is specifically tailored for Ubuntu 18.04. While some of the troubleshooting steps may work for other versions of Ubuntu, it’s recommended to refer to version-specific guides for the best results.
If switching to the default GNOME display manager doesn’t resolve the issue, you can proceed with creating the configuration file and power cycling the dock as outlined in the troubleshooting steps.
If you are experiencing issues with the DisplayPort not being detected on your ThinkPad USB-C dock, and you have exhausted all other troubleshooting steps, it may be worth considering a firmware update. Refer to the manufacturer’s instructions or visit the official Lenovo support website for guidance on how to check and update your dock’s firmware.
While ThinkPad USB-C docks are generally compatible with Ubuntu 18.04, there may be occasional compatibility issues or limitations depending on the specific hardware configuration and software updates. It’s recommended to stay up to date with the latest Ubuntu and dock firmware updates to minimize any potential compatibility issues.
Yes, you can try using a different dock with your ThinkPad T480s on Ubuntu 18.04. However, it’s important to ensure that the dock is compatible with your laptop and that proper drivers are available for Ubuntu.