I am affected by the bug without having upgraded from trusty to xenial. I simply upgraded from kernel 3.13 to kernel 4.4 maintaining the Trusty release.
After the kernel upgrade the touchpad of my Dell XPS 13 ( version 9333 - 2014 ) is no more recognized as a valid input source for the xserver. It is useful to point out that I also own a newer Dell XPS 13 ( version 9350 -2016 ); the machine came with a more recent trusty version ( Ubuntu 14.04.5 LTS ). After upgrading from kernel 3.19 to kernel 4.4 the touchpad is still working without a glitch. I guess that something has gone wrong when upgrading the kernel in the older machine. I tried to install package xserver-xorg-input-synaptics with the following result: sudo apt-get install xserver-xorg-input-synaptics The following packages have unmet dependencies. xserver-xorg-input-synaptics : Depends: xorg-input-abi-20 Depends: xserver-xorg-core (>= 2:1.14.99.902) E: Unable to correct problems, you have held broken packages. It is likely that the actual origin of the bug lies in the above mentioned broken packages ... -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1629613 Title: [Dell XPS 13] SynPS/2 Synaptics TouchPad not recognized after upgrade from 14.04 to 16.04 Status in linux package in Ubuntu: Confirmed Bug description: * Touchpad doesn't work at all (No response from the Touchpad) * Tried using external mouse and it works fine * Cannot find "SynPS/2 Synaptics TouchPad" in "cat /proc/bus/input/devices" OS: Ubuntu 16.04.1 LTS kernel version: 4.4.0-38-generic Laptop Model: Dell XPS 13 - 93333 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1629613/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp