How to make the Latitude 7490 trackpoint enjoyable in Linux

Everybody knows about the fantastic Thinkpad trackpoint feeling, but what about the Dell one? Well, the hardware is now quite good apart from the nub cap. But the software, as with any trackpoint in Linux, is still lackluster. For example, in Linux you don’t get the middle-button scrolling by default, arguably one of the most useful feature of a trackpoint.

The nub

Disclaimer

Those suggestions only works with X11, I don’t know how to tweak this settings with Wayland. Let me know if you find a way to make it works with the new framework.

So, let’s fix it!

In Linux, you can control input devices mainly with two different tools: evdev and libinput.

  • evdev: generic input interface in the kernel, that old guy;
  • libinput: the new shiny stuff that technically sit on top of the evdev interface. It’s the only way to go with Wayland.

While libinput is the default and what should be used today, as every new project it does not support every feature of evdev, E.G. our beloved middle button scrolling; it should come soon some in one of the next releases, but it’s still not there. So, we will revert back to evdev about the trackpoint handling, for now.

In order to do that, we need to create /etc/X11/xorg.conf.d/10-trackpoint.conf . The file name is not important apart for the initial NN- part.

Reboot your machine, and everything should work. I’ve tested this configuration with kernel > 4.12, but I think it should work with older version without issues.

Addition tweaks

Some evdev input options, as far as I know, aren’t directly accessible via the Xorg configuration files, but you can use it via the mighty xinput. For a list of supported devices:

Be careful with devices IDs, they vary wildly between reboots. If you want to script something, always filter the devices by name. For example, we can list the tunable properties of our trackpoint.

One of the few stuff missing is the “Device Accel Constant Deceleration”, AKA the pointer sensitivity. Oh, and the horizontal scrolling. You can adjust them with a pair of commands.

I think that’s all for now, I hope that the Wayland-libinput support will be ready soon… feel free to tell me when this mini-tutorial will became obsolete, and enjoy your Latitude!