Comment # 19 on bug 1132943 from Michael Hirmke

(In reply to Takashi Iwai from comment #18)
> Thanks.  So something else must be the culprit.
> 
> Meanwhile, could you check the latest 5.1-rc upstream kernel in OBS
> Kernel:HEAD repo?  If this shows the same problem, we'll need to ping the
> upstream dev immediately.  (Note that this also needs to disable the secure
> boot.)
> 
> OTOH, if 5.1-rc kernel works, it means some incomplete backport in 5.0.x.

No, sorry to tell, but 5.1-rc6 still has the problem.