Re: [PATCH] ptp/ptp_clock.c: Correct input parameter range check

[Siddaraju DH]

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Thank you for the response with example Richard.
Agree, it works. So I take back the statement in my commit message
"Since the tv_sec field will be ZERO in this range, the user will not
be able to specify the signedness of adjustment through the tv_sec
field".

Specifying a -1 ns adjustment like
    tv_sec = 0
    tv_nsec = -1
looks pretty straight forward than specifying it like
    tv_sec = -1
    tv_nsec = 999999999.

And the former way of specifying the adjustment is consistent with how
we specify the values for positive adjustments.

So, the question is "why are we blocking -ve number in tv_nsec"? As
you mentioned, end of the day it's sum of tv_sec & tv_nsec.
If there is really an advantage, just to keep things clear, we could
have made tv_nsec/usec as "unsigned long" instead of "long". Right?
For me, it doesn't look good to expect/restrict a signed input to be unsigned.

Thanks,
Siddaraju DH