Comment 3 for bug 1644719

Test again and can not reproduce this issue.

Steps
1. install oem image
2. sudo apt-get update and dist-upgrade to kernel version as following

Linux u-Precision-5510 3.19.0-75-generic #83~14.04.1-Ubuntu SMP Thu Nov 10 10:51:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
touchpad is still workable

3. enable -proposed updates
4. sudo apt-get update & upgrade

result
touchpd is still working

u@u-Precision-5510:~$ xinput
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ ELAN Touchscreen id=12 [slave pointer (2)]
⎜ ↳ SynPS/2 Synaptics TouchPad id=14 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
    ↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
    ↳ Power Button id=6 [slave keyboard (3)]
    ↳ Video Bus id=7 [slave keyboard (3)]
    ↳ Video Bus id=8 [slave keyboard (3)]
    ↳ Power Button id=9 [slave keyboard (3)]
    ↳ Sleep Button id=10 [slave keyboard (3)]
    ↳ Integrated_Webcam_HD id=11 [slave keyboard (3)]
    ↳ AT Translated Set 2 keyboard id=13 [slave keyboard (3)]
    ↳ Dell WMI hotkeys id=15 [slave keyboard (3)]
    ↳ Intel HID event filter id=16 [slave keyboard (3)]