[LinuxPPS] LinuxPPS, kernel 4.4, ntpd 4.2.8

[Joachim Fabini]

Btw, I was contacted off-list: a user tried the proposed solution and it
works on a Raspberry Pi, too. About a year ago he asked repeatedly for
support on the ntp questions list but received no reply.
(https://www.mail-archive.com/questions@lists.ntp.org/msg25441.html)

The main question from my perspective is whether a) the conditional has
mistakenly been removed by the ntp maintainers as part of a code cleanup
(the conditional reads like an undocumented "lex LinuxPPS") or b) ntp
4.2.8 relies on some additional time_pps_kcbind() functionality that is
effectively missing in LinuxPPS.

The practical experiments (includign the conditional patch) suggest that
the LinuxPPS functionality seems to be sufficient for ntp pps. However,
a confirmation is badly needed.

I guess that this may require some joint effort of LinuxPPS and ntp
maintainers. As a first step I filed a ntp bug report at
http://bugs.ntp.org/show_bug.cgi?id=3367

best regards
Joachim


On 11.01.2017 17:24, Udo van den Heuvel wrote:
> On 10-01-17 20:14, Joachim Fabini wrote:
>> Can someone familiar with LinuxPPS and/or ntp confirm this diagnosis? Or
>> disprove it? This means that ntp 4.2.8 _could_ provide PPS functionality
>> in theory but in practice it does NOT because a developer has decided
>> (for whatever reason that is not known to me) to remove a conditional.
> 
> If I understand your explanation correctly when can patch the
> conditional back in and then we should see a functional 4.2.8.
> 
> If you can test that you can prove that just the conditional is the
> issue here.
> 
> My Fedora 24 is at 4.2.6 still. Rawhide has ntp 4.2.8.
> 
> Kind regards,
> Udo
>