Ok, I've now built and tested a kernel with 4.4 + the below commit and can confirm that this commit fixes the touchpad issue for me.
commit 8a7fa6187191f005d4b6d29913de6e128cc778e2 Author: Benjamin Tissoires <benjamin.tissoi...@redhat.com> Date: Tue Dec 1 12:41:38 2015 +0100 HID: multitouch: fix input mode switching on some Elan panels ** Bug watch added: Linux Kernel Bug Tracker #108481 http://bugzilla.kernel.org/show_bug.cgi?id=108481 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1540511 Title: Touchpad not working (4.3 -> 4.4 regression) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1540511/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs