Comment # 8 on bug 1203505 from Takashi Iwai

Now I took a deeper look at the current code.  It seems that the backport patch
  patches.suse/iommu-vt-d-Acquiring-lock-in-domain-ID-allocation-helpers
doesn't fit well with SLE15-SP4 code.  It missed the removal of spinlock from a
couple of places, and it resulted in a spin deadlock.

I'm building a test kernel with the corrected patch.  It's being built in OBS
home:tiwai:bsc1203505 repo.  Once after the build finishes (takes an hour or
so), the test kernel package will appear at
  http://download.opensuse.org/repositories/home:/tiwai:/bsc1203505/pool/

Can anyone give it a try later?