Comment 12 for bug 1180881

More finding, if suspend/resume doesn't work for you, try the following steps
   cd /sys/devices/pci0000:00
   find -name control | xargs -I '{}' sudo sh -c "echo on > '{}'"
   sudo pm-suspend
It will turn on the power for all devices, more precisely you can just turn on the usb host chip's power
   cd /sys/devices/pci0000:00/0000:00:14.0
   find -name control | xargs -I '{}' sudo sh -c "echo on > '{}'"
   sudo pm-suspend

It works for me every time, so it's more like a power management issue from Synaptics touchscreen firmware.