Comment # 2 on bug 1233134 from Takashi Iwai

Is it a complete kernel hang-up, or is it just a graphics problem?  i.e. you
can't access remotely via ssh?

Also, please check with the latest SLE15-SP5 kernel in OBS Kernel:SLE15-SP5
repo
  https://download.opensuse.org/repositories/Kernel:/SLE15-SP5/pool/

If the problem persists, we'd need to get the crash log.  e.g. you can disable
the drm kernel modules in initrd via dracut option, also blacklisting amdgpu.
Then after the system boots up, load amdgpu module manually and get the kernel
messages.  At best, try to set up kdump and get the full dmesg output.