Bug#944758: Problem solved

Reason was either some amdgpu-pro package or updating libegl to git version.

Bug#944758: xserver-xorg-video-amdgpu version too old

Package: xserver-xorg-video-amdgpu Version: 19.1.0-1 The version is not compatible with xserver-xorg-core 2:1.20.4-1. Does not boot to desktop.

Bug#889483: libegl1 disables amdgpu drm with Buster mesa

Reopen this bug, the log file shows that this bug is for Debian Buster Mesa.

Bug#889483: libegl1 package disables amdgpu direct rendering

Package: libegl1 Version: 1.0.0-2 The presence of this package disables 2d and 3d hardware acceleration of the Mesa amdgpu driver: [ 6.245] (EE) AMDGPU(0): eglGetDisplay() failed [ 6.245] (EE) AMDGPU(0): glamor detected, failed to initialize EGL. [ 6.452] (II) AMDGPU(0): Front buffer pitch: 768