Change in flashrom[staging]: ich_descriptors: Fix off-by-one error

[Nico Huber (Code Review)]

Nico Huber has posted comments on this change. ( https://review.coreboot.org/20937 )

Change subject: ich_descriptors: Fix off-by-one error
......................................................................


Patch Set 1:

(2 comments)

https://review.coreboot.org/#/c/20937/1//COMMIT_MSG
Commit Message:

https://review.coreboot.org/#/c/20937/1//COMMIT_MSG@9
PS1, Line 9: The "number of masters" (NM) reflects the value that begins at 1.
Seems that this is right for Lewisburg, awesome! more mess
for us to handle.

I've never found a definition if it starts at 0 or 1 and past
practice was to count from 0 (== 1 master)! All descriptors
in the wild that I've encountered were for platforms with 3
masters and always had NM set to 2 ;) Now the SPI guide for
Lewisburg states it should be 6 (and there are only 6 masters
mentioned), hmmm.

I guess the lack of an explicit definition confused Intel's
developers even more than us and now they disagree. No prob-
lem for them, as they make one (binary) program for each
platform anyway (I suppose).

Two solutions come to mind: Take the guessed platform into
account (Lewisburg would need its own constant). Or we could
ignore a too high NM and just return MAX_NUM_MASTERS (and
drop a lot of sanity checks as we could return an unsigned
value).


https://review.coreboot.org/#/c/20937/1//COMMIT_MSG@17
PS1, Line 17: even more wrong than it was before.
I don't see any loop doing it wrong, nor any caller adding 1
to the return value.



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Gerrit-Project: flashrom
Gerrit-Branch: staging
Gerrit-MessageType: comment
Gerrit-Change-Id: I92627332265cf79720b98241d73bc36b1f6a7167
Gerrit-Change-Number: 20937
Gerrit-PatchSet: 1
Gerrit-Owner: David Hendricks <[e-mail]>
Gerrit-Reviewer: Nico Huber <[e-mail]>
Gerrit-Reviewer: Paul Menzel <[e-mail]>
Gerrit-Reviewer: Stefan Tauner <[e-mail]>
Gerrit-Reviewer: build bot (Jenkins) <[e-mail]>
Gerrit-Comment-Date: Thu, 10 Aug 2017 11:55:24 +0000
Gerrit-HasComments: Yes