Keyboard and mouse unresponsive after suspend

Reinstall or install input device drivers.

sudo apt-get install xserver-xorg-input-all 

Or:

sudo apt-get install --reinstall xserver-xorg-input-all

I've tried all the answers on this page, but they didn't really work. I thought reinstalling xserver-xorg-input-all worked, but it didn't. I recently found this page and the freezing hasn't happened since. What you do is edit /etc/default/grub and change GRUB_CMDLINE_LINUX_DEFAULT to have the value "atkdb.reset i8042.nomux quiet splash" and then run sudo update-grub and reboot. This also works on 16.04.

In my case it had something to do with the graphics card driver and this fixed me (if you use some latest nvidia graphics card then getting the updated driver may work) --

sudo apt-get install nvidia-current-updates