[OLED] Gamescope(?) hangs/freezes external applications when switching from fullscreen to windowed while rendering something using vulkan.

[Haxorzz]

Your system information

• Steam client version: 1704936806
• SteamOS version: 3.6 20240104.1
• Opted into Steam client beta?: [Yes]
• Opted into SteamOS beta?: [Yes]
• Have you checked for updates in Settings > System?: [Yes]

Please describe your issue in as much detail as possible:

I expected the application to go from fullscreen to windowed and vice versa with no issue. Instead sporadically (more often than not) the application seems to instantly hang when going back from fullscreen and the only way to stop the hang is by going fullscreen (usually via a shortcut) and triggering some overlay like the exit confirmation pop up. This usually also required the app to be actively rendering something like a game or a 3d scene using vulkan. If you try the fix without going back into fullscreen, it usually does atleast draw the application's interface but with issues like not properly redrawing the UI over the last rendered game frame. I am not aware of this occuring on the LCD steam deck.

Steps for reproducing this issue:

1. Launch a flatpak or appimage in game mode
2. Go exclusive fullscreen (usually rendering something like a game using vulkan)
3. Use a shortcut or similar to go back to windowed (Hangs here)

It is slightly sporadic as sometimes it seems to go into windowed with some slight issues like application UI not redrawing right.

[Haxorzz]

Similar issue experienced by this issue and much more similar to the comments ValveSoftware/gamescope#1040

[Haxorzz]

This Reddit thread and the comments have the exact same issue. Seems like this is specific to vulkan

[godfreyatlast]

Same issue here, however with the yuzu emulator. Screen image freezes when not in full screen, resumes when returning to full screen. Interestingly, this only happens when the Vulcan driver is used.