d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Clarify hardpps() parameter name and comment

Browse Source 
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
This commit is contained in:
Sebastian Huber 2023-01-25 13:43:11 +01:00 committed by Warner Losh
parent df949e762c
commit c7c53e3ca6
1 changed files with 5 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
sys/kern/kern_ntptime.c
View File

@ -733,11 +733,11 @@ hardupdate(offset)
* variables, except for the actual time and frequency variables, which
* are determined by this routine and updated atomically.
*
* tsp - time at PPS
* nsec - hardware counter at PPS
* tsp - time at current PPS event
* delta_nsec - time elapsed between the previous and current PPS event
*/
void
hardpps(struct timespec *tsp, long nsec)
hardpps(struct timespec *tsp, long delta_nsec)
{
long u_sec, u_nsec, v_nsec; /* temps */
l_fp ftemp;
@ -774,12 +774,9 @@ hardpps(struct timespec *tsp, long nsec)
/*
* Compute the difference between the current and previous
* counter values. If the difference exceeds 0.5 s, assume it
* has wrapped around, so correct 1.0 s. If the result exceeds
* the tick interval, the sample point has crossed a tick
* boundary during the last second, so correct the tick. Very
* intricate.
* has wrapped around, so correct 1.0 s.
*/
u_nsec = nsec;
u_nsec = delta_nsec;
if (u_nsec > (NANOSECOND >> 1))
u_nsec -= NANOSECOND;
else if (u_nsec < -(NANOSECOND >> 1))