DRI3 Full screen corruption regression in OpenArena

Submitted by Daniel Drake @dsdrake1

Assigned to xf86-video-ati maintainers

Link to original bug (#111389)

Description

When starting OpenArena fullscreen under GNOME, the screen becomes corrupt and the game is unplayable (see attached photo).

This has been reproduced on:

1. Ubuntu Eoan 19.10 nightly using OpenArena from Flathub
   
2. Ubuntu Eoan 19.10 nightly using OpenArena from Ubuntu packages after configuring it to enter fullscreen mode
   
3. Endless OS 3.6.2 using OpenArena from Flathub
   

The same tests on machines that use i915 or amdgpu graphics do not reproduce the problem.

Back on the radeon device, I also found the problem does not occur if you first use xrandr to change display mode to 640x480 (so that running the game does not require it to change the display mode). Alternatively, configure it as:
Option "DRI" "2"
and the issue is fully avoided (even when the game changes the display mode during launch)

This worked fine on older distro versions, so it appears to be a recent regression and I bisected it down to:

55e513b9 is the first bad commit
commit 55e513b9
Author: Michel Dänzer
Date: Sat Apr 29 17:05:58 2017 +0900

Use reference counting for tracking KMS framebuffer lifetimes


Please let me know how we can help debug further.