Flickering screen after upgrading to 5.15.5 kernel

There are numerous reports on the internet of people experiencing screen flickering on Linux kernel 5.15.*. If you experience these kind of issues, the best option may be to switch to another kernel, until this has been resolved.

You can check your current kernel like so:

$ uname -a
Linux panther 5.15.10 #1 SMP 1 x86_64 GNU/Linux

To switch to another kernel, you need to modify the system configuration:

su - root
# emacs offers the best support for scheme (.scm) files
nano /etc/system.scm

Modify your configuration like this:

(use-modules (gnu)
             (gnu system)
             (px system install)
             (px system)
             ;; Add these two lines                                                                                                                                                        
             (nongnu packages linux)
             (nongnu system linux-initrd))

(px-desktop-os
 (operating-system
  (host-name "pantherx-7ym7vd")
  (timezone "Europe/Berlin")
  (locale "en_us.utf8") 

  ;; Add these three lines                                                                                                                                                                   
  (kernel linux-5.10)
  (initrd microcode-initrd)
  (firmware (list linux-firmware))

  ;; Other stuff                                                                                                                                                                  

  (services (cons*
             %px-desktop-services)))
  
  ;; Add this line                                                                                                                                                                        
  #:kernel 'libre)

To apply these changes, run (as root):

guix system reconfigure /etc/system.scm

Simply reboot after the operation has completed.