Comment 54 for bug 1746740

Oh, ok. I wasn't skilled enough to run all the tests freedesktop asked. I don't know if a single sample as given there by Sean IIRC is enough accurate for such a HID that may have its sensitivity range spread around some typical value supplied by the manufacturer. Then maybe it would be worth converting the values from xserver-xorg-input-synaptics to libinput as at least in my l322x, the touchpad was really easy to use.
Whatever, Thanks Ubuntu teams