Comment # 3 on bug 1219522 from Takashi Iwai

(In reply to Edwin KM from comment #2)
> I am hesitant to install kernels. My grub list contains 3 items. 2 broken.
> If it will remove my working kernel i can not boot anymore.

Increase the number of installable kernels by editing /etc/zypp/zypp.conf
before installing more test kernels.  Add entries in multiversion.kernels line,
e.g.
  multiversion.kernels = latest,latest-1,latest-2,latest-3,running
so that the system can keep more kernel packages.

> Also unclear which rpm i should install.

Just kernel-default.rpm should suffice.