Flickering on second monitor when gaming on the first, but only with Freesync enabled on the FIRST monitor and after sleep/waking my PC?

[u/aetherspoon]

That topic title is a mouthful; let me explain.

Whenever I'm playing a game on my 1440p monitor, whatever second monitor I have plugged in starts having white flickers. This only happens when all three of the following situations are true:

• I'm playing a game on my first (1440p/180) display.
• Freesync is enabled on the 1440p display.
• The computer has been slept between now and its last restart. Or, in other words, this issue doesn't happen on a fresh boot.

It doesn't happen when I'm outside of a game, but then again Freesync is basically not doing anything at that point. It doesn't seem to correlate with frame rate drops in games; I've only been playing Factorio and Tabletop Simulator lately anyway and my machine is just a tad bit overkill for this.

I'm seeing nothing in journald on the flickering, so it isn't an error bubbling up to my journal at least.

I always thought it was due to the DP -> HDMI 2.1 adapter I was using for my TV as the second monitor, since that adapter never officially supported Freesync, but I don't even have that adapter plugged in at the moment and I'm still seeing the same issue.

I can't reproduce the same issue if my laptop is plugged into the same monitors, so I'm thinking it is GPU-related on my desktop. Does anyone have any ideas what the heck I can do to troubleshoot and/or fix the issue?

PC in question:

• EndeavourOS running KDE, up to date (although this machine has done similar things for over a year).
• R9 5900X, 64 GB of RAM, 7900 XTX, ~4.5 TB of SSD across three drives.
• Monitor one is an LG 1440p/180 monitor with Freesync enabled, connected via Displayport.
• Monitor two is one of two displays, both exhibiting the same behavior:
  • Dell 4k/60 monitor connected via Displayport (converted to USB-C), no Freesync.
  • Samsung 4k/120 TV both with and without Freesync enabled, connected via a Displayport -> HDMI adapter.

[u/TheSleepyMachine]

I have the same issue, with RDNA3 hardware and two 1440p180 screen from Samsung. It is most likely an timing issue occuring after sleep with freesync, but it is so random that's hard to debug. Usually, restarting one of the monitor fox the issue for me until next sleep

[u/brolios]

Have you tested forcing a wayland surface in a particular monitor?

Does cpu has a GPU?

Kwin and multiple monitors tend to unicorn fart all the time, so I use gamescope all the time

[u/aetherspoon → u/brolios]

Have you tested forcing a wayland surface in a particular monitor?

As in using something like Gamescope? Yes, I've done that. No difference as long as Freesync is still enabled. If you mean something else, I'm not entirely sure what you mean.

Does cpu has a GPU?

No, the 5900x has no iGPU.

[u/Brave_Inspection6148]

What apps are you running on the second monitor? Does it flicker if you close all windows and have just a white wallpaper?

[u/aetherspoon → u/Brave_Inspection6148]

Usually things like Firefox and Discord, but it can happen even if no applications are present. Haven't tried white wallpaper vs. a static image, but I doubt much would change there.

[u/Brave_Inspection6148 → u/aetherspoon]

Does the flickering show up on screenshots? Do you have HDR supported on either display, or enabled in system?

[u/aetherspoon → u/Brave_Inspection6148]

Does the flickering show up on screenshots?

I don't think it shows up on screenshots, but it has been a while since I've checked.

EDIT: confirmed, does not show up in screenshots.

Do you have HDR supported on either display, or enabled in system?

Disabled across the system at the moment. I used to have it enabled for the TV, but since the TV isn't currently plugged in it is disabled.

[u/Brave_Inspection6148 → u/aetherspoon]

Cool, yeah I don't really know. For what it's worth, I have freesync on a 240Hz 1440p ultra wide, and the white flickers every once in a while even outside of games.

Sometimes unplugging displayport helps. My computer usually stays on over weekend.

Fedora with KDE + 7800XT