AMD+Wayland+dual monitor = Screen flickering
So...I have an...interesting behavior I've never had before with an Nvidia or integrated intel chipsets...I have now my AMD card plugged both to a normal HDMI monitor, and then to another HDMI TV. Both work well. However, when I turn the TV off... The monitor will start flickering. About three flickers every minute or so. It's not a signal loss also, I can see it's drawing for a brief split second the windows that were drawing on the TV area, so it's kinda rearranging the whole desktop area...then it resets. It does this 3 times, the whole ordeal last a couple seconds, in which everything is unusable because of the flicker, and focus going to all sorts of places. If I turn the TV back on, the behavior stops immediately.
Any idea what's causing this, and how can I sort it out? I'm using KDE Neon latest (it's still Ubuntu 22.04), with an AMD 7800XT, with kisak's ppa. Running an updated kernel 6.5.0-1007-oem. (I followed these instructions to get it working at all)
You could try disabling VRR in your display settings. I believe it is set to auto by default if supported, but it does not work properly for some monitors causing flickering.
Hmm, I can't say I've seen that before. However, it might be worthwhile trying to just boot a live ISO of GNOME (or any other DE) just to rule out a KDE issue. Then if that doesn't replicate the problem, try a live distro of something with a newer version of KDE (such as Fedora 39).
At the very least, that'll help narrow down where the problem might be coming from!
That sounds like your TV is temporarily disconnecting at random, or at least doing something that the GPU detects as a disconnect.
Most likely, AMD's hotplug detection is too aggressive. You can report that at https://gitlab.freedesktop.org/drm/amd/-/issues
I have this same issue, but not for a TV. Just a normal Asus monitor. If I use my laptop built-in panel and the gaming monitor, it happens less. If I enable a third monitor, it happens nearly every time I try to log back in.
Sleep/standby is disabled on mine cuz no distro I've found can work properly with it so it's just turning the monitors back on really.
It also happens exiting a game sometimes.
I've found waiting it out doesn't work, I have to fight through it to open display settings and disable one of the external monitors, then hit revert. Then it's back to normal.
Edit adding some info since our hardware is different: Lenovo legion slim Nvidia 4050 ryzen 5 Kubuntu 23.10
If you disable the TV display first, then turn it off, does the flickering happen?
Thinking that the TV is periodically connecting and your desktop environment is trying to switch to dual monitors before quickly losing the TV connection.
I think it's indeed related to detecting the TV on and off. On the previous PC (this one is just brand new) this didn't happen.
I was getting flickering when my monitors were on, last tine I tried Wayland a month or two ago. Probably not the same issue, but these sorts of issues is keeping me on X.
It could be some weird sleep behavior bug, or since it's KDE, it could be another of the 5 gajillion daily bugs of KDE