Comment 10 for bug 1779092

I wanted to shed some more light on this issue and our decision making after hearing of at least one person that saw this update and thought that this was a regression in the microcode provided by AMD. While we don't yet know the actual cause of this issue, a regression introduced in the microcode itself is not at the top of our list of suspicions. We haven't heard of any similar reports in Ubuntu 16.04 LTS, Ubuntu 17.10, or Ubuntu 18.04 LTS which all received the same microcode updates.

We suspect that it has something to do with the combination of 3.13 kernel's support for early microcode loading, the packaging for the amd64-microcode package, and/or the initramfs generation when injecting new AMD microcode. We're still investigating the cause and will release additional updates when we've tracked down the solution.