Clarify hardpps() parameter name and comment
Since 32c203577a
by phk in 1999 (Make even more of the PPSAPI
implementations generic), the "nsec" parameter of hardpps() is a time
difference and no longer a time point. Change the name to "delta_nsec"
and adjust the comment.
Remove comment about a clock tick adjustment which is no longer in the code.
Pull Request: https://github.com/freebsd/freebsd-src/pull/640
Reviewed by: imp
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@ -733,11 +733,11 @@ hardupdate(offset)
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* variables, except for the actual time and frequency variables, which
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* are determined by this routine and updated atomically.
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*
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* tsp - time at PPS
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* nsec - hardware counter at PPS
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* tsp - time at current PPS event
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* delta_nsec - time elapsed between the previous and current PPS event
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*/
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void
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hardpps(struct timespec *tsp, long nsec)
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hardpps(struct timespec *tsp, long delta_nsec)
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{
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long u_sec, u_nsec, v_nsec; /* temps */
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l_fp ftemp;
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@ -774,12 +774,9 @@ hardpps(struct timespec *tsp, long nsec)
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/*
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* Compute the difference between the current and previous
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* counter values. If the difference exceeds 0.5 s, assume it
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* has wrapped around, so correct 1.0 s. If the result exceeds
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* the tick interval, the sample point has crossed a tick
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* boundary during the last second, so correct the tick. Very
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* intricate.
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* has wrapped around, so correct 1.0 s.
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*/
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u_nsec = nsec;
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u_nsec = delta_nsec;
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if (u_nsec > (NANOSECOND >> 1))
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u_nsec -= NANOSECOND;
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else if (u_nsec < -(NANOSECOND >> 1))
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