Due to boo#1172905 I recently switched from 'kernel-firmware-all' to
'kernel-firmware' package to work around this bug.

This didn't quite work as I expected. Removing 'kernel-firmware-all' would
leave the remainder of the 'kernel-firmware-*' packages installed and I had to
zypper lock the 'kernel-firmware-all' package after deinstallation. Otherwise
'zypper dup' would insist on reverting back to 'kernel-firmware-all' and
removing 'kernel-firmware'.

As I understand 'kernel-firmware-all' and 'kernel-firmware' are mutually
exclusive and although the first may be preferred over the latter upon first
installation, once a choice is made (for whatever reason), zypper should not
change to the other.