@rikuv also look more closely at that patch
in upstream coreboot docs, it says grub hangs on those hp laptops (grub coreboot payload)
riku fixed it, by adding a 200ms timeout in grub's ps/2 init. see:
i advised riku to submit this upstream to the gnu project and/or coreboot (on coreboot side, if not merged in grub upstream, hotpatch at build time)
libreboot has that patch now applied automatically when building grub
it might benefit other machines too (timeout code)