Comment # 25 on bug 935086 from Takashi Iwai

BTW, while looking at the dmesg output on my machine, I noticed that the system
triggers hibernate-resume twice: once the kernel itself and once by dracut.

Could you add "noresume" boot option (while keeping "resume=xxx" option) and
retest for a few times whether you still get the unexpected reboot with
SLEEP_METHOD="kernel"?

Also does this have any influence with SLEEP_METHOD="uswsusp"?