Comment # 14 on bug 1156053 from Michal Kube��ek

(In reply to Berthold Gunreben from comment #13)
> (In reply to Jiri Slaby from comment #12)
> > And what about this (when it gets built):
> > https://download.opensuse.org/repositories/home:/jirislaby:/bnc1156053/
> > openSUSE_Factory_zSystems
> > ?
> 
> I just installed it to my existing tumbleweed installation, and after
> booting that kernel, iucvconn did work without issues.

So the (only) problem indeed is that DMA kmalloc caches have usercopy disabled
(unlike regular ones). Unfortunately the commit message of commit 6c0c21adc742
does not provide any explanation or clue why.

> The only message in dmesg that appeared is:
> 
> [   52.188783] NET: Registered protocol family 32

32 is AF_IUCV so this is expected.