My advice is to not run ANY OS in EFI mode on recent Samsung computers. As described by Matthew Garrett, this firmware can be bricked even from Windows. The initial Linux kernel fix just fixed the most common path to the underlying bug, but the bug remained. I've heard a vague report that there may be a second workaround in even more recent kernels, but I don't have details and I don't know if this really completely eliminates the risk.
Given all this, my advice is to do one of three things:
- Return the computer to the store for a refund and buy something that's not defective.
- Wipe the hard disk clean and re-install everything you want to use in BIOS mode rather than in EFI mode.
- Put the computer back in its box until Samsung releases a fixed firmware.