Comment # 6 on bug 1013200 from Stefan Dirsch

Hmm. The only difference in xorg-x11-server between 42.2 release and update I
can find is

 U_modesetting-set-driverPrivate-to-Null-after-closing-fd.patch
 Prevent crash when unplugging displaylink device. (bnc#1011570)

I don't think this is the culprit and it only affects modesetting driver users,
which you probably are not with your AMD card (check /var/log/Xorg.0.log or
wherever your displaymanager writes the X log into).

> (from the "official" http://download.opensuse.org/repositories/Kernel:/stable/standard/ repository) 
>

For sure this is not the "official" kernel. This is a bleeding edge
"kernel-of-the-day". Therefore I suggest to go back to our latest Leap 42.2
kernel (version 4.4!) and test again.

For me this looks like a race between plymouth and X. Honestly if you can live
without a splash screen for boot I recommend to disable plymouth by adding
"plymouth.enable=0" to the kernel boot options. ;-)