i915 refresh on UHD770 lagged/disturbed

[sh]

kernel-version: Ubuntu 5.15.0-41.44~20.04.1-generic 5.15.39
xorg-core: 2:1.20.13-1ubuntu1~20.04.3

cpu: 12th Gen Intel(R) Core(TM) i5-12600
gpu: VGA compatible controller: Intel Corporation Device 4690 (rev 0c)

problem: depending on how the layers are used by different programs the display is disturbed by slow refresh. it takes up to 2-3 seconds until the layer is shown without errors.

(it's afresh install, tested until now:
- firefox: very slow refresh for all menus and gagets, on scrolling or playing video
- scribus: slow refresh on menus and gadgets, no problem with the pages
- remote-viewer (spice): slow refresh on menus and gadgets, a few problems with the screen (even with firefox in kvm)
- libreoffice, gimp, inkscape: no problems

tried all combinations of i915-options for enable_guc={0..3}, enable_fbc={0,1} with no difference (firmware loaded was tgl_guc_62.0.0.bin, tgl_huc_7.9.3.bin depending on options)

but if the i915-driver is deactivated (accidently made a syntax-error at options, which leads to self-deactivation of the driver), no such problems are seen (unfortunately the second port is unusable then -- and before anyone asks: even if i915 is loaded and only one monitor is connected, the problems occure)

as explanation, how these errors look, I've made a picture of a text-only-webpage (no javascript) during scrolling (this is extreme, but is best for showing the horizontal fragments)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1982850

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[sh (qbuzpxrhc2sj)]

this command isn't available, because it's a linuxmint-install, but linuxmint says, that this kind of bug should be filed here due the unchanged origin of the kernel: https://linuxmint-troubleshooting-guide.readthedocs.io/en/latest/where.html

nevertheless all necessary information should be noted in the inital bug-msg. if there's anything special missing, please note this and we'll try to collect the needed info.