Display artifacts on COSMIC Wayland with AMD iGPU + external monitor

[simo1616]

Problem

I get visual display artifacts on COSMIC Wayland with an AMD iGPU and an external monitor.

The artifacts appear as flickering / corrupted colored blocks on the screen. They can affect both the laptop display and the external HDMI monitor.

They are visible to the eye, but they do not appear in OBS recordings or screenshots.

Setup

• OS: Pop!_OS 24.04 LTS
• Session with issue: COSMIC / Wayland
• Working session: XFCE / X11
• CPU/GPU: AMD Ryzen 7 7730U with Radeon Graphics
• Driver: amdgpu
• External monitor: Samsung Odyssey G5 over HDMI

Tests done

• COSMIC / Wayland: artifacts happen
• XFCE / X11: no artifacts
• Kernel 6.18.7: artifacts happen
• Kernel 6.17.9: artifacts happen
• Removed NVIDIA packages and removed nvidia-drm.modeset=1
• Tried amdgpu.dcdebugmask=0x10: no change
• Lowered external monitor resolution to 2560x1440 @ 60 Hz: no change

Relevant logs

amdgpu: [drm] Failed to setup vendor infoframe on connector HDMI-A-1: -22
workqueue: dm_handle_vmin_vmax_update [amdgpu] hogged CPU for >13333us
[drm] Mode Validation Warning: Unknown Status failed validation.
WARNING ... dcn20_find_secondary_pipe ... [amdgpu]
amdgpu_dm_atomic_check
drm_mode_atomic_ioctl
cosmic-comp: Failed to set xwayland primary output: The provided output wasn't known to Xwayland

[simo1616]

Update:

I tested the workaround suggested in a similar issue:

COSMIC_DISABLE_DIRECT_SCANOUT=y

I added it through /etc/profile.d/ and rebooted.

After logging back into COSMIC Wayland:

echo $COSMIC_DISABLE_DIRECT_SCANOUT
# y

echo $XDG_SESSION_TYPE
# wayland

The artifacts are gone with this workaround.

So the issue seems related to COSMIC direct scanout with amdgpu / AMD display pipeline.

[SpasMilenkov]

just want to do a +1 here, this fixes it for me too

[AndrewBilello]

+1 as well. Same issue. Same workaround also successful.

However, lowering my monitor from 2560x1440 @ 165hz to 2560x1440 @ 120hz seems to also fix the issue, but it's display port.

Cosmic desktop and AMD GPU

[riverfr0zen]

Is there a downside to setting COSMIC_DISABLE_DIRECT_SCANOUT=y? It seems it causes the app to bypass the compositor when fullscreen--what functionality is lost when that happens?

[ChonkyMonkey]

+1 fixed it for me

[HigorChagas]

+1, this fixes it for me too.

[DSTGU]

Can confirm both the issue and the fix.

I'm on nvidia driver Pop 24.04 with amd igpu and a 1650ti (mobile).

Video of the bug occuring to me:
https://drive.google.com/file/d/1gIsSzEA4QRiVfDA4msNbAY9aL0UaTWij/view?usp=drive_link

[willkimen]

I'm having the same issue here. It's so annoying.

[Delta-Azura]

COSMIC_DISABLE_DIRECT_SCANOUT=y

It worked, thank you.
@leviport @mmstick This bug is really annoying and it happens even on pop os with the amd|nvidia iso designed especially for this kind of hardware targeted by the iso.

[moofree]

I just updated for the first time in a couple months and am getting this issue on my 6900XT.

COSMIC_DISABLE_DIRECT_SCANOUT=y
I added it through /etc/profile.d/ and rebooted.

How exactly do you do this? This directory has a few scripts but I'm not sure what to actually do.

[riverfr0zen]

I just updated for the first time in a couple months and am getting this issue on my 6900XT.

COSMIC_DISABLE_DIRECT_SCANOUT=y
I added it through /etc/profile.d/ and rebooted.

How exactly do you do this? This directory has a few scripts but I'm not sure what to actually do.

Create a file as root in the folder, e.g. sudo nano /etc/profile.d/my_vars.sh (or your favorite editor)

and in the file add

export COSMIC_DISABLE_DIRECT_SCANOUT=y

Save the file and make sure users have read permissions:

sudo chmod ugo+r /etc/profile.d/my_vars.sh