System freeze after suspend

Solution 1:

I have a 4.19 kernel and Nvidia driver version 390. I changed gdm to lightdm.

sudo apt install lightdm

Problem is solved now.

Solution 2:

After using Ubuntu 16.04 LTS for a few days and everything was OK, I started to experience this freeze on suspend/sleep. I reinstalled the lightdm display manager and the problem didn't go away. I had similar logs to yours, but no hard errors.

What solved the problem for me was changing the default X.org video driver to the NVidia one.

This is located in Settings -> Software & Updates -> Additional Drivers

There I had the following option selected.

'Using X.org X server - Nouveau display driver...'

After changing it to:

Using NVidia binary driver ... (proprietary, tested)

Restart and everything is fine since then :)

Solution 3:

I have had the same problem with Ubuntu 20.04 since installing some time ago - freezing on going into suspend - could only be dealt with by holding down the power-button for some six seconds or so. Tried all manner of suggestions - including those given above - but nothing worked, UNTIL I used the "Software & Updates" app to upgrade and, Hey Presto, all fixed!

Hope it works for you too.