Comment 0 for bug 1591669

This is on a Dell XPS 13 9350 DE running ubuntu 16.04.
This laptop has a touchpad and a touchscreen.
I'm reporting here about the touchpad.

One can see from Xorg.0.log and "xinput list" that *two* touchpads are registered by the system

one is called "DLL0704:01 06CB:76AE Touchpad"
and the other "SynPS/2 Synaptics TouchPad"

As a result, syndaemon is not working.
To check this, open two terminals, press and hold some key, like "e" in one of them. It starts filling with "eeeeeee". Now while holding the key, use the touchpad to tap on the other terminal. Then "eeee" fills the new terminal.
Expected behaviour:
tapping on the other terminal should have no effet, the "e"'s should continue to fill the first terminal.

Moreover, configuring the touchpad with synclient is not working either.

FIX:

Since invoking
xinput disable "SynPS/2 Synaptics TouchPad"
has no effect, it is clear that this one is a "false" touchpad.

Hence this fix is:
Add an "ignore" section in /usr/share/X11/xorg.conf.d/50-synaptics.conf

I added, line 29:

Section "InputClass"
        Identifier "touchpad ignore SynPS/2 Synaptics duplicate"
        MatchProduct "SynPS/2 Synaptics TouchPad"
        Option "Ignore" "on"
EndSection

Now it works. The touchpad is correctly disabled when using the keyboard, and moreover I can configure it using synclient, or adding a file to /etc/X11/xorg.conf.d/

Of course this fix is not universal because I had to use the precise name of the "false touchpad" as reported by xinput.