Bug 483418

Summary:	On Wayland with 2 monitors, severe flickering on the one plugged into an NVIDIA GPU
Product:	[Plasma] kwin	Reporter:	Hosein <hosein.lavaei.06>
Component:	multi-screen	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	major	CC:	hosein.lavaei.06, nate, vlad.zahorodnii, xaver.hugl
Priority:	NOR	Keywords:	multiscreen, wayland
Version:	6.0.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Hosein 2024-03-13 09:51:36 UTC

I have enabled drm mod setting
I didn't have this issue on plasma 5.
My computer has an Nvidia GTX 1650 with latest drivers installed and an Intel integrated GPU
I have two monitors. I connect one of them to the integrated GPU and another to my Nvidia.
I see so many flickering on monitor that is connected to Nvidia.
It's notable that if I connect just one of them and not two of them it works

Comment 1 Nate Graham 2024-03-13 21:30:06 UTC

Which one flickers? Is it always the one plugged into the NVIDIA GPU?

Comment 2 Nate Graham 2024-03-13 21:30:20 UTC

Also, is this happening on X11, or Wayland, or both?

Comment 3 Hosein 2024-03-14 01:26:39 UTC

(In reply to Nate Graham from comment #1)
> Which one flickers? Is it always the one plugged into the NVIDIA GPU?

Yes

Comment 4 Hosein 2024-03-14 01:26:59 UTC

(In reply to Nate Graham from comment #2)
> Also, is this happening on X11, or Wayland, or both?

Just Wayland

Comment 5 Hosein 2024-03-14 01:28:19 UTC

It's also notable that if I run sddm with wayland and kwin it does not flicker

Comment 6 Nate Graham 2024-03-14 16:29:54 UTC

Thanks.

Comment 7 Zamundaaa 2024-03-15 02:10:51 UTC

Do you see the flickering only in some apps, or on the whole screen?

Comment 8 Hosein 2024-03-15 10:11:07 UTC

(In reply to Zamundaaa from comment #7)
> Do you see the flickering only in some apps, or on the whole screen?

On the whole screen. When some app or cursor refresh whole monitor will flicker

Comment 9 Zamundaaa 2024-03-15 18:54:53 UTC

Okay, that's pretty odd then. What version of the proprietary drivers are you on? I can't see any flickering with 550

Comment 10 Hosein 2024-03-23 19:01:49 UTC

(In reply to Zamundaaa from comment #9)
> Okay, that's pretty odd then. What version of the proprietary drivers are
> you on? I can't see any flickering with 550

Latest. 555

Comment 11 Hosein 2024-03-23 19:04:08 UTC

(In reply to Hosein from comment #10)
> (In reply to Zamundaaa from comment #9)
> > Okay, that's pretty odd then. What version of the proprietary drivers are
> > you on? I can't see any flickering with 550
> 
> Latest. 550

Comment 12 Hosein 2024-03-23 19:05:35 UTC

Sorry. I checked now it's 550. I made a mistake

Comment 13 Hosein 2024-03-25 16:00:23 UTC

i run kwin-wayland command and findout that it flickers in kwni itself too.
guess the problome is with kwin. 

i also checked logs. didnt find anything related

Comment 14 Zamundaaa 2024-03-25 17:14:52 UTC

hmm yeah nested kwin wayland flickering isn't entirely surprising, we'll need to implement explicit sync in it. Can you file a separate bug report for that please?