psmouse serio2 psmouse.synaptics_intertouch=1

[    4.315902] psmouse serio2: synaptics: Your touchpad (PNP: SYN1219 PNP0f13) 
says it can support a different bus. If i2c-hid and hid-rmi are not used, you 
might want to try setting psmouse.synaptics_intertouch to 1 and report this to 
linux-input@vger.kernel.org.

I'd like to report this as being told. If you need any further information 
please ask me. I'm happy to answer any questions.

psmouse.synaptics_intertouch=1 works fine.

-- 
Mit freundlichem Gruß, André Najda