Table of Contents

Ubuntu - GPU - Nouveau - Switch back to nouveau driver

sudo apt update
sudo apt install xserver-xorg-video-nouveau

NOTE: Can also use the GNOME GUI Software & Updates application window, to switch to the nouveau driver.

Reboot

Reboot for the changes to take effect. 

sudo reboot

Confirm the nouveau modules are loaded

sudo lsmod | grep nouveau

returns: 

nouveau              1949696  4
mxm_wmi                16384  1 nouveau
ttm                   106496  1 nouveau
drm_kms_helper        184320  1 nouveau
drm                   491520  7 drm_kms_helper,ttm,nouveau
i2c_algo_bit           16384  1 nouveau
wmi                    32768  3 wmi_bmof,mxm_wmi,nouveau
video                  49152  1 nouveau