https://bugs.freedesktop.org/show_bug.cgi?id=109628
--- Comment #34 from Chris Snook chris.snook@gmail.com --- (In reply to Chris Snook from comment #33)
(In reply to Johannes Hirte from comment #28)
From the reports, it seems to be compositor related. For me, kwin with OpenGL 3.1 backend works fine. xfwm4 seems to trigger the bug, maybe other compositors too.
Confirmed that the workaround of switching to the kwin OpenGL 3.1 compositor works for me.
kernel: 5.3.0-19-generic (Ubuntu 19.10) window manager: kwin-x11 4:5.16.5-0ubuntu1 CPU: Ryzen Pro 2500U machine: Lenovo Thinkpad A485 X server: xserver-xorg 1:7.7+19ubuntu12 userspace driver: xserver-xorg-video-amdgpu 19.0.1-1ubuntu1
I'm happy to test patches or reproduce.
I may have spoken too soon. I'm non-deterministically experiencing the basic symptom of hang on resume with a blank screen, sometimes with the backlight on and sometimes without, but I no longer get the traceback in logs, so I can't tell if it's mostly the same bug but without tripping the failure mode that causes it to log, or if there's an unrelated suspend/resume bug. Switching to the OpenGL 3.1 compositor has definitely made that error message stop appearing in my logs though.