SDDM login: lags / flickering when loggin in

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1

Hello,

long ago, I set up my desktop to use the same picture as background for the login screen (sddm), for login animation and as background to the final desktop. This resulted in a smooth transition from hitting “ENTER” after typing in my password, to the working desktop, without any flickering between the three phases of the login procedure.

Now, after upgrading to Plasma 6.7.2, there are two black screens between the three phases of the login procedure, each lasting about a tenth of a second. I guess that’s when the system want’s to load the “new” picture for the next phase, which really is the same as before.

Is there any way I can get rid again of these two lags?

Some important data that might be useful for giving any hint:

Operating System: KDE neon User Edition
KDE Plasma Version: 6.7.2
KDE Frameworks Version: 6.28.0
Qt Version: 6.11.1
Kernel Version: 6.8.0-134-lowlatency (64-bit)
Graphics Platform: X11

It does not matter whether I use X11 or Wayland, the lags happen anyway. And I would like to stick to X11 for now.

Thanks in advance for any clue or help.

2

Hi there!

Have you heard any of the Legends of Plymouth?

That’s just my current guess, as I just stumbled upon it yesterday after a couple/few months of flickering screens.

I stumbled upon a cachyos forum post regarding a tutorial to disable/remove the plymouth boot splashes, where plymouth’s job is to make the entire boot process seemless by starting with the prefered native resolution as soon as possible. Too bad most EDID configs are…just at varying levels of being incorrect, if they aren’t outright corrupted in the first place.

…that’s just my best guess right now; where the kernel is being dragged into native resolutions and detailed resolutions (currently, at that time) reported as the connected display’s EDID. I’m mentally working up to the point of gutting it out of my cachyos–a freshy–install.

Cheers! -J-

3

Thanks for your respond and your idea! It was a good one, but plymouth is not causing the two black screens. I purged everything that has the string “plymouth” in its title, kernel init ram disk was recreated, but after a reboot those two black screens still appear.