swaymsg output disable: gray screen above 60 Hz

[Dominik-Zehnter-17]

Sway Version:
sway version 1.10.1 (Debian Trixie, Kernel 6.12.17, Radeon RX 7800 XT)

Debug Log:
https://gist.github.com/Dominik-Zehnter-17/e035bb99616a7c66bff600b5c1dc6273

Configuration File:
https://gist.github.com/Dominik-Zehnter-17/81c8436573faee2a33df7e08ef871b41
[Default file plus monitors set above 60 Hz]

Description:
I have three 4k monitors running at 144Hz. When I only need one of them, I use shortcuts to run

exec swaymsg output DP-2 disable
exec swaymsg output DP-3 disable

Most of the time, this results in the DP-1 monitor displaying a solid gray color. The monitor does not lose signal. Sway is still functional, responds to keyboard inputs, audio works and new windows can be spawned, they are just obscured by the solid gray screen. The gray screen disappears when running

exec swaymsg output DP-1 disable
exec swaymsg output DP-1 enable

or re-enabling a second monitor

exec swaymsg output DP-2/DP-3 enable

This issue does not occur when running the monitors at the default 60Hz, but occurs at both 120 and 144Hz.

[mm1ke]

i guess you having the same issue as me - see #8445

[Dominik-Zehnter-17]

You're right, your description is basically identical, it happens about 90% of the time without any apparent cause. Does setting your monitors to a lower refresh rate fix the issue? Running at 60Hz does for me, which I find curious

[emersion]

I couldn't find anything relevant in the logs.

[Dominik-Zehnter-17]

That's too bad. I did some further digging and confirmed the bug on GNOME and KDE, both running on Wayland and Xorg. Running the monitors at 60Hz "fixes" the bug. I confirmed the bug does not occur on Windows 11.

Strangely, disabling adaptive sync (freesync) in the monitor's OSD also always fixed the issue across all compositors.

Consider

output DP-0 resolution [email protected] adaptive_sync on (hardware enabled)
output DP-1 resolution [email protected] adaptive_sync on (hardware not enabled)

The gray screen issue occurs on DP-0 when

 swaymsg output DP-1 disable

bot not on DP-1 when

 swaymsg output DP-0 disable

Disabling adaptive sync in software does not work, it has to be disabled on the hardware side. It would be great if @mm1ke could confirm my results. Where should this bug be reported, since it is apparently neither exclusive to sway nor to Wayland?

[Dominik-Zehnter-17]

I also observed that the screen does not turn completely gray, a few lines of pixels in the top left corner are unobscured, not that I think it matters

[emersion]

If the bug also happens on other compositors, this is likely a kernel driver issue. Please open a bug report there.