This shows how the Validity Sensor 138a:0090 fingerprint sensor can be made to work on Linux. This Sensor is used in various ThinkPads such as the X1 Carbon (4. Gen) or in my case the X1 Yoga (1. Gen).

First is to note that this is how I got the sensor on MY setup and this post exists for MY documentation. None the less this maybe helpful to someone.

I run bedrock linux with Fedora being my main distro, but having some packages from Arch.

  1. Make sure to have fprintd installed in both Fedora and Arch and fprintd-pam in Fedora.

  2. The libfprint patch for the vfs0090 sensor needs to be installed from the AUR: libfprint-vfs0090-git.

  3. Edit the fprintd.service file on Fedora to execute fprintd from arch:

    (This is the hacky part)

    /bedrock/strata/fedora/usr/lib/systemd/system/fprintd.service

    ExecStart=/bedrock/bin/strat arch /usr/lib/fprintd

    Make sure fprintd is systemctl enable’d.

  4. Enable fingerprint authentication in Fedora:

    # authselect enable-feature with-fingerprint

(This was figured out over weeks and may need reboots in between steps or other changes I forgot to mention)