Re: [Dle-develop] [RFC][PATCH v3 2/3] Skip spin_locks in panic case and add WARN_ON()

[Luck, T. <ton...@in...>]

> I'll ask an Intel EFI guru whether I'm on target.

Got a short note back from the EFI people:

----
The reason the paragraph exists in 7.1.1 is that certain services (as listed
in table 31) are guaranteed to work if you call them a second time when you
have taken an exception in trying to execute them already -- say SetVariable()
face plants with an exception...because of the way our code is designed you
can call it a second time even if the first call that took the exception
didn't succeed.

At any rate, I checked with a couple of the other experts around us and none
of us can see any reason to send yourself an NMI just to preface a call to
a UEFI runtime service.  Thus, our collective opinion is that you are correct
in your interpretation.
----

If you want to discuss this more - they apparently have an external mailing
list some place on TianoCore.org. But this seems pretty clear that we don't
need to self-NMI.

-Tony