I didn't see this issue in the last cycle,
it seems that this issue will just happen about once per year (2016 Nov, 2017 Aug, 2018 Sep), when the grub-ieee1275 got updated.
Maybe the update between these two versions can give some clues?
I will check it again when we have the proposed Trusty kernel.
Hi Mathieu,
I didn't see this issue in the last cycle,
it seems that this issue will just happen about once per year (2016 Nov, 2017 Aug, 2018 Sep), when the grub-ieee1275 got updated.
Maybe the update between these two versions can give some clues?
I will check it again when we have the proposed Trusty kernel.