I few months ago, I added a Logitech T650 touchpad to my desktop setup. After a firmware update (one that had to be done via Windows–shame on you Logitech), the touchpad worked flawlessly under Ubuntu 14.10. Single-tap, double-tap, scrolling, and some gestures made my daily grind a little bit less, well, grindy.
But then I opted to make the leap to Ubuntu 15.04 and, out of nowhere, the touchpad wasn’t working nearly as well. What happened? Oddly enough, the latest kernel finally received built-in support for touch devices.