X240 trackpoint speed

The screen on my X1 Carbon gave out after a couple months, and my loaner laptop in the meantime is an X240.

The worst thing about this laptop is how slowly the trackpoint moves with a default Ubuntu installation. However, it’s fixable:

cat /sys/devices/platform/i8042/serio1/serio2/speed
cat /sys/devices/platform/i8042/serio1/serio2/sensitivity

Note the starting values in case anything goes wrong, then fiddle around:

echo 255 | sudo tee /sys/devices/platform/i8042/serio1/serio2/sensitivity
echo 255 | sudo tee /sys/devices/platform/i8042/serio1/serio2/speed

Some binary search themed prodding and a lot of tee: /sys/devices/platform/i8042/serio1/serio2/sensitivity: Numerical result out of range has confirmed that both files accept values between 0-255. Interestingly, setting them to 0 does not seem to disable the trackpoint completely.

If you’re wondering why the configuration settings look like ordinary files but choke on values bigger or smaller than a short, go read about sysfs.