Comment 181 for bug 1166442

This affects my laptop (Lenovo Yoga 3 11.6" 2-in-1):

ubuntu@ubuntu:~$ lsusb
Bus 001 Device 002: ID 8087:8001 Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 006: ID 8087:07dc Intel Corp.
Bus 002 Device 005: ID 1bcf:2c43 Sunplus Innovation Technology Inc.
Bus 002 Device 004: ID 04f3:2052 Elan Microelectronics Corp.
Bus 002 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 002 Device 002: ID 058f:6387 Alcor Micro Corp. Flash Drive
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Presumably the touchpad is the following line then:
  Bus 002 Device 004: ID 04f3:2052 Elan Microelectronics Corp.

Excerpt of /proc/bus/input/devices:

I: Bus=0018 Vendor=04f3 Product=0400 Version=0100
N: Name="ELAN0600:00 04F3:0400"
P: Phys=
S: Sysfs=/devices/pci0000:00/INT3433:00/i2c-8/i2c-ELAN0600:00/0018:04F3:0400.0003/input/input13
U: Uniq=
H: Handlers=mouse1 event12
B: PROP=0
B: EV=17
B: KEY=30000 0 0 0 0
B: REL=143
B: MSC=10

The touchscreen works fine, as well as both left and right clicks. Just the multitouch doesn't work at all.

More details on the system:

ubuntu@ubuntu:~$ uname -a
Linux ubuntu 3.16.0-23-generic #31-Ubuntu SMP Tue Oct 21 17:56:17 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@ubuntu:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.10
Release: 14.10
Codename: utopic

Also I grepped syslog for elan:
ubuntu@ubuntu:~$ grep -i elan /var/log/syslog
Feb 17 01:53:37 ubuntu kernel: [ 17.373586] usb 2-5: Manufacturer: ELAN
Feb 17 01:53:38 ubuntu kernel: [ 28.061105] input: ELAN Touchscreen as /devices/pci0000:00/0000:00:14.0/usb2/2-5/2-5:1.0/0003:04F3:2052.0001/input/input11
Feb 17 01:53:38 ubuntu kernel: [ 28.067747] hid-multitouch 0003:04F3:2052.0001: input,hiddev0,hidraw0: USB HID v1.10 Device [ELAN Touchscreen] on usb-0000:00:14.0-5/input0
Feb 17 01:53:38 ubuntu kernel: [ 28.272108] i2c_hid i2c-ELAN0600:00: error in i2c_hid_init_report size:633 / ret_size:7
Feb 17 01:53:38 ubuntu kernel: [ 28.274418] i2c_hid i2c-ELAN0600:00: error in i2c_hid_init_report size:69 / ret_size:7
Feb 17 01:53:38 ubuntu kernel: [ 28.274589] input: ELAN0600:00 04F3:0400 as /devices/pci0000:00/INT3433:00/i2c-8/i2c-ELAN0600:00/0018:04F3:0400.0003/input/input13
Feb 17 01:53:38 ubuntu kernel: [ 28.275039] hid-generic 0018:04F3:0400.0003: input,hidraw1: <UNKNOWN> HID v1.00 Mouse [ELAN0600:00 04F3:0400] on

AFAICS the issue still affects Vivid too.