Comment 11 for bug 1629613

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 ...