https://bugs.freedesktop.org/show_bug.cgi?id=93767
--- Comment #5 from Nicolai Hähnle nhaehnle@gmail.com --- Hi Daniel, thanks for the apitrace and preliminary investigation. I can confirm that the trace shows a rendering error on Verde, Bonaire, and Tonga. A workaround for now is to set R600_DEBUG=nohyperz.
Could you please test whether the problem appears also on lower MSAA levels?
almos, I'm surprised that you're not seeing the glitch. What's your system setup and hardware?
A proper fix may involve disabling ALLOW_EXPCLEAR for MSAA stencil.