Triggering OSD while having any game open, makes my screen to turn black.

[Reason7322]

Hello.

Ever since ive swapped my config from hyprlang to lua ive been dealing with a bug that makes my screen to go black anytime i trigger an audio pop up, while using Noctalia shell.

Whenever i have a game open(it doesnt matter if its a native linux game, or one running through proton, it doesnt matter if its running through xwayland, gamescope makes no difference, fullscreen vs borderless makes no difference either) and then i trigger an audio volume popup, my screen goes black for a ~second, and when im done adjusting the volume, the popup dissappears, and my screen goes black again for a ~second. However, if the game has HDR on, the screen doesnt go black, the colors, the saturation, the contrast gets changed instead.

The only way to prevent this, is by removing/commenting out this config line in my hyprland config:

direct_scanout = true

hyprland.txt
systeminfo.txt

When i was using hyprlang for my config, it never has happened.

Ive reported this issue to Noctalia devs - noctalia-dev/noctalia#2695 (comment)

I obviously do not have to use Noctalia shell, but it used to work without an issue in the past.

Ive tried troubleshooting it with Claude, everything below this point has been written by it:

Bug: Brief black screen when OSD/layer surface appears while any game is running

System:

• OS: CachyOS (Arch-based)
• Kernel: 7.0.1-1-cachyos
• Hyprland: 0.55
• GPU: Sapphire RX 9070 XT Pulse 16GB (RDNA4, gfx1201)
• Monitor: Dell Alienware AW2724DM 2560×1440 180Hz via DisplayPort 1.4
• Desktop shell: Noctalia v5.0.0
• Config: Lua

Description:

Whenever any game is running and a layer surface appears (Noctalia volume OSD in this case), the screen briefly goes black for a fraction of a second before returning to normal. This happens consistently and repeatedly every time the OSD is triggered.

Reproduction steps:

1. Launch any game
2. Trigger any layer surface (e.g. adjust volume to show OSD)
3. Screen goes black briefly

What was tested and ruled out:

Variable | Test | Result -- | -- | -- DSC | debugfs dp_dsc_fec_support | FEC_Sink_Support: no, DSC_Sink_Support: no, all DSC values 0 — DSC not active, monitor doesn't support it GPU load | glmark2-wayland running, OSD triggered | No black screen — GPU load alone is not the trigger Fullscreen state | glmark2-wayland fullscreened via compositor, OSD triggered | No black screen — fullscreen state alone is not the trigger XWayland | L4D2 launched with PROTON_ENABLE_WAYLAND=1 (xwayland: 0 confirmed via hyprctl clients), OSD triggered | Black screen still occurs — not an XWayland-specific issue Proton/Wine | Native L4D2 and Wine NFS Most Wanted 2005 both reproduce it | Compatibility layer is irrelevant Steam process tree | NFS Most Wanted via Wine (no Steam involved) reproduces it | Steam is not the cause GameMode | L4D2 launched without gamemoderun, glmark2 launched with gamemoderun | No difference in either case VRR mode | Tested modes 0, 1, and 2 | No difference cm_auto_hdr | Tested 0 and 1 | No difference allow_tearing | Toggled | No difference Resolution/refresh rate | Reproduced at 1080p@60Hz | Not a bandwidth or timing issue Kernel/driver | Tested on same machine, same GPU, same kernel series — Nobara with KDE Plasma 6.6.4 | Bug does not occur on Nobara — rules out GPU driver and kernel as cause

The one consistent distinguishing factor that remains unexplained:

glmark2-wayland does not trigger the bug under any tested condition (windowed, fullscreen, with or without GameMode, native Wayland). Every actual game triggers it regardless of compatibility layer, window mode, or launch method. The specific difference between glmark2 and a game process that causes this has not been identified.

Relevant hyprctl clients output:

glmark2 (does NOT trigger bug):

class: com.github.glmark2.glmark2
xwayland: 0
fullscreen: 0
overFullscreen: 0
contentType: none

Slay the Spire 2 (triggers bug):

class: gamescope
xwayland: 0
fullscreen: 2
fullscreenClient: 2
overFullscreen: 1
contentType: none

NFS Most Wanted 2005 via Wine (triggers bug):

class: speed.exe
xwayland: 1
fullscreen: 2
fullscreenClient: 2
overFullscreen: 1
contentType: none

L4D2 native Wayland (triggers bug):

class: steam_app_550
xwayland: 0
fullscreen: 2
fullscreenClient: 2
overFullscreen: 1
contentType: none

Note: glmark2 fullscreened via compositor keybind also shows overFullscreen: 1 but still does not trigger the bug, so overFullscreen alone is not the trigger either.

Conclusion:

Since the bug is absent on the same hardware under KDE Plasma but present under Hyprland, and survives all the above variable eliminations, the cause appears to be in Hyprland's handling of layer surface compositing when a game-class window is present. The specific code path that differs between glmark2 and an actual game process has not been identified and likely requires compositor-level instrumentation to find.

[Reason7322]

It also happens if i do not run any kind of shell, a Steam notification can trigger that behavior as well.

[wabarTM]

This is expected behaviour with DS enabled, monitor is simply modesetting because the app went fullscreen and notification goes over it. Either disable DS or dont have any popups.

Direct scanout attempts to reduce lag when there is only one fullscreen application on a screen (e.g. game).

[njdom24]

That's not the full picture. I've experienced that this happens when the full-screened app is of a different bit depth / buffer format than what the display is set to. Say your monitor is set to 10-bit and you're playing a 8-bit game, Hyprland will modeset in and out of 8-bit when you go in and out of fullscreen.

Since no other compositor does this, and it's rather disruptive, I feel there should be an option to disable direct scanout for a format mismatch, if such a modeset can't be done without the display blanking.

[Reason7322]

This is expected behaviour with DS enabled, monitor is simply modesetting because the app went fullscreen and notification goes over it. Either disable DS or dont have any popups.

Direct scanout attempts to reduce lag when there is only one fullscreen application on a screen (e.g. game).

That didnt used to happen on Hyprland 0.54

[UjinT34]

DS has a lot of conditions to be able to activate, simply enabling it in the config doesn't mean that it'll be used. Newer HL versions are able to activate DS in a wider range of circumstances. That includes using more of the drm properties and modifying them accordingly some video driver and monitor combos will do it seamlessly others will have a black screen for some time. That time might be longer than the notification duration. Try setting the duration higher. If the issue persists for the entire time the notification is on screen no matter how long it is then it's a bug. If black screen appears for a fixed amount of time during DS activation-deactivation then it's the issue with your hw that might or might not be fixed with future HL updates (overlay planes and drm color pipeline). You can try setting render:non_shader_cm = ignore. That'll cause oversaturated SDR colors in DS mode but will update fewer drm properties during DS activation-deactivation. If this doesn't help then it's very likely that DS wasn't working for you in 0.54 and you can just disable the feature.

[FakeMichau]

Hey would you be able to check if your issue might be caused by the same things as my issue? #15881
Noctalia creates notifications on a new top layer -> that layer shows over a FS game even tho it shouldn't -> that breaks DS