SDDM login glitch after changing GPU

Ask Fedora
1

Greetings.
I am using Fedora Workstation 41, with nvidia drivers installed by following this guide.

I have recently swapped my RTX 3060 card with a GT 1030. Everything works as expected, except a minor screen glitching whenever I login with SDDM.

here is the chronology (video below):

  1. I get greeted by SDDM, asks me to enter password
  2. I enter password, then login
  3. A glitchy screen filled with random-ish artifacts… like TV static, but with multiple colours. This stays for roughly a second
  4. The KDE splashscreen starts, as expected
  5. I get dropped to desktop when everything has finished working

Only the #3 point is the weird thing, otherwise everything works just like before.

I have tried re-installing nvidia drivers by first sudo dnf remove nvidia\* , then re-following the guide. Nothing changed.

Perhaps, there is some “setting” file that I can delete/reset? Thanks…

Note: This is happening only during login and logout. locking screen and then unlocking does not trigger the glitch

Edit: I have added some videos to exactly show what is going on.

Login Video demonstration

Logout video demonstration

2

Edit2: I have also deleted ~/.cache/ and /var/lib/sddm/cache, no change…

3

Hmm… after a little more tinkering, I found out removing quiet from the command line args fixes this.

I guess removing quiet causes new stream of output to be displayed and somehow “clears” previous “screen buffer”? I say this because the glitch screen sometimes also showed “ghost log” of previous shutdown message from dual booting another linux drive (I have an old install of opensuse TW in another drive, and it is configured to show verbose boot/startup logs)

Excuse me if I don’t make any sense, I have 0 knowledge and I am just assuming out of thin air :stuck_out_tongue:

Not exactly a “solution”, I would love for an expert to chime in and give their thoughts on why this could be happening…