https://bugs.freedesktop.org/show_bug.cgi?id=101946
--- Comment #3 from Robin beanow@oscp.info --- What I noticed from the kern.log is that it seems to try and skip init steps the second time amdgpu loads. So perhaps the unbind doesn't do a clean enough shutdown or there may be a bug in the init step skipping.
For example, the first time:
[ 129.439652] amdgpu 0000:01:00.0: enabling device (0000 -> 0003) ... [ 129.918128] [drm] GPU posting now...
The second time: No mention of enabling device.
[ 159.722828] [drm] GPU post is not needed