Should the HAVE_KERNEL_PLL conditional be abolished?
Hal Murray
hmurray at megapathdsl.net
Mon Dec 4 19:35:35 UTC 2017
>> >> First: capture pulse timing info.
>> >> Second: adjust "drift" on system clock
>> >> Third: in kernel PLL to adjust drift from PPS pulses
> You need drift correction implemented in the kernel to get decent
>> timekeeping. ntp_adjtime is just the API.
> For the drift correction, yes. Am I correct that it doesn't do the other
> two things?
Yes. The PPS stuff uses time_pps_*
No man pages. I assume everybody follows the RFC.
Turning on/off the kernel PLL uses time_pps_kcbind
On linux, it's an ioctl via PPS_KC_BIND
details in /usr/include/linux/pps.h and /usr/include/sys/timepps.h and
ntpd/ntp_refclock.c
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