How to reload Nvidia driver, (Nvidia Optimus/multiscreen: How to restart optirun after hibernation/suspend)

Question

I use the following scripts to initialize multiscreen setup:

#!/bin/bash
# Initializes Nvidia Optimus for multi-screen functionality.

sudo modprobe bbswitch
optirun true
intel-virtual-output

But when my machine suspends, it goes back to a single screen. I try to restart by terminating and initializating again. I terminate with the following:

sudo kill -15 $xorg_process
sudo rmmod nvidia
sudo tee /proc/acpi/bbswitch <<<OFF

Then I run the initialize script again, but I get the following message:

[16929.676769] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) Server terminated successfully (0). Closing log file.

[16929.676811] [ERROR]Aborting because fallback start is disabled.

Manual testing indicates that this error comes from the optirun true command in the initialize script. Is there a way I can reload my second screen after my machine hibernates? (or, more specifically, how to reload the Nvidia driver?)

I am referencing the solution to the Optimus multiscreen monitor issue (for machines with outputs hard-wired to the discrete GPU) found here.

Answer 1

The following works for me on a Thinkpad T520 under arch:

Before suspending:

killall Xorg
sudo rmmod nvidia
sudo modprobe bbswitch
sudo tee /proc/acpi/bbswitch <<< OFF
sudo systemctl stop bumblebeed

After resume:

sudo rmmod nvidia
sudo modprobe nvidia
sudo modprobe bbswitch
sudo systemctl start bumblebeed
sudo tee /proc/acpi/bbswitch <<< ON
optirun true
intel-virtual-output

Especially reloading the nvidia kernel module seems to do the trick for me here.