I've been getting some reports that the kernel is not fully quiet /
the boot is not fully smooth / flickerfree when using secure boot.
This is fixed by this patch:
I believe that this patch is safe, so I plan to add it as
downstream patch to the F29+ kernels for now.
But this is early boot code so you never know. Hence the heads-up,
if there are mysterious boot failures this might be the culprit
(it would be weird if it is, but you never know).