Hi, I am currently unable to boot a Yoga 900 with latest mainline, but 4.8 boots.
The symptom is a reboot before the video console is available. I bisected to commit 816e76129ed5 "efi: Allow drivers to reserve boot services forever". However, that commit is known to be broken. The proposed fix, commit 92dc33501bfb "x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE", also exhibits the reboot problem. During the bisect some of the stopping points landed on commits that caused the boot process to hang rather than cause a reboot. The commits that resulted in a hang are marked "git bisect skip" in this log: https://gist.github.com/djbw/1b501daa98192a42ae848f03bb59c30e I'll try treating those hangs as bad bisect results and re-run the full bisect tomorrow. In the meantime I wonder if the bisect log implicates a better regression candidate?