Sunday, November 13, 2022

How to: restore Nouveua video drivers on Fedora 36 (Related: Clean up after failed Nvidia installs on Fedora 36 KDE-Plasma)

 Status

Confirmed by lack of nonoccurence of this issue.

 History

I recently "moved into" my new workstation at home. As usual, it came with a Microsoft product (which wasn't too bad, honestly) but I wanted to use Fedora KDE-Plasma.  I started the process and got a clean separation between "What Is Windows" and "What is Fedora".

As almost every other time in the past, I wanted to use NVidia video drivers.  And, as iwth almost every other time, I failed to get NVidia to install correctly for Fedora.  I don't think it's necessarily RedHat's fault, probably 1/3 NVidia's issue and the rest is my issue. I simply can't invest several days to teach myself how to build (easy), install (seemed easy but didn't work) and configure (never get that far.) 

So, I "rolled back" to the always working Nouveua video driver.  After a bit, I thought I had safely returned to the land of productive.  After a few kernel updates, I discovered I was wrong. 1024x768 worth of wrong.

 Overview

Prior NVidia video driver installs had left several, disabling files and configurations.

Constraints

Wanted to restore Nouveua video drivers to full operability without reinstalling the OS Fedora 36 KDE-Plasma.

Preparations

  1. Followed the instructions here: Uninstall the NVIDIA driver
  2. Taken from the console output of NVidia driver installer process, I removed:
    1. /usr/lib/modprobe.d/nvidia-installer-disable-nouveau.conf
    2. /etc/modprobe.d/nvidia-installer-disable-nouveau.conf
  3. rebooted, dnf updated and rebooted again

Process Issues

This process worked well for about 3 weeks. I kept my  OS and applications up to day (dnf and flatpak.)  However, after Fedora updates proved on 12 November arrived, these seemed to trigger an unexpected and silent event.  After shutdown and restart on 13 November, I was greeted with persistent, non-complaining 1024x768 and no options to restore functionality.  In contrast: I normally operate my video at 5120x1440.

Steps

Check Journal (inconclusive)

journalctl -p err..alert -b

Summary

I spend some time here as there is a lot of "red noise" to filter though. After a bit, I determined the issues displayed did not strong contributors to my display issue.

 Check XOrg (inconclusive)

less /var/log/Xorg.0.log

Summary

Nothing much to see here. I was looking here to see if XWindows listed what video driver it was using. 

Check Boot.log (inconclusive)

cat /var/log/boot.log

Summary

No errors found.

Check /boot (definitive)

grep -R nouveau /boot/

Summary

Here I found the core issue:

/boot/grub2/grub.cfg:  set kernelopts="root=UUID=0xxxxxx9-9xx1-4xx4-9xxc-axxxxxxxxxxf ro rootflags=subvol=root rhgb quiet rd.driver.blacklist=nouveau modprobe.blacklist=nouveau nvidia-drm.modeset=1 "

Nvidia's installation had disabled Nouveau when booting the kernel but NVidia's uninstall instructions did not handle the grub2 configuration nor do I recall seeing any mentioned else where.

Solution

grubby --update-kernel=ALL --remove-args='rd.driver.blacklist=nouveau'
grubby --update-kernel=ALL --remove-args='modprobe.blacklist=nouveau'
grubby --update-kernel=ALL --remove-args='nvidia-drm.modeset=1'

 
Summary
grubby is the official way to change values for the Grub2 boot configuration.

Note: these changes appear to be persistent after a reboot. I am uncertain if these changes alone are enough.  After the next kernel and/or Grub2 update, I should know for certain.

Summary

Grubby is used to modify the boot parameters for Fedora 36 installations.  It can be used to add and remove "at kernel boot time" configurations.  Responsible software vendors should pay equal attention to how their software is uninstalled as to how it is installed.

Resources

Other Resources

Disclaimer

This solution worked for me. It may or may not work for you. I am not responsible for your actions nor the your results of your actions should you act on what you read here. I do not claim expertise in this very specific area and only convey my experience. There is no warranty on this (and most) free information.