[L] Change in flashrom[main]: udelay: only use OS time for delays, except on DOS

[Peter Marheine (Code Review)]

Attention is currently required from: Anastasia Klimchuk, Brian Norris, Thomas Heijligen.

Peter Marheine has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/81545?usp=email )

Change subject: udelay: only use OS time for delays, except on DOS
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Patch Set 9:

(4 comments)

Commit Message:

https://review.coreboot.org/c/flashrom/+/81545/comment/27cac6b1_03442abc :
PS7, Line 10: )
> you can also add the link to archive (keep the title) https://mail.coreboot. […]

Done

File tests/udelay.c:

https://review.coreboot.org/c/flashrom/+/81545/comment/84c49c7f_92768e76 :
PS7, Line 47: default_delay(100);
> I thought for a moment we can afford a long delay test, for usec = 100001, but I don't know would it […]

I think it's most useful to be testing the short delay case, since it's easy to understand the situations in which it should sleep and we depend on the OS for ensuring a sleep is long enough.

My goal here was to have some confidence that timer-polling waits won't terminate early, and in that context I don't think it's very useful to exercise a long wait.

File udelay.c:

https://review.coreboot.org/c/flashrom/+/81545/comment/6ac9c6a0_18bf2605 :
PS7, Line 33: #ifdef _POSIX_MONOTONIC_CLOCK
            : static clockid_t clock_id = CLOCK_MONOTONIC;
            : #else
            : static clockid_t clock_id = CLOCK_REALTIME;
            : #endif
> This is only used inside `clock_usec_delay` now, can it be locally defined inside the function? It w […]

Done

https://review.coreboot.org/c/flashrom/+/81545/comment/66d4ec8e_574ea1f2 :
PS7, Line 62: inline
> For my education, why the function is inline only for this case and not the above?

That's how it was before; no reason as far as I'm concerned. I've removed the inline.