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Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. r
From: |
Gary E. Miller |
Subject: |
Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. release-3.11-46-g6a33950 |
Date: |
Wed, 27 Aug 2014 14:49:28 -0700 |
Yo Greg!
I never siad it workedopn NetBSD, just that the TIOCMIWAIT is ifdefed out.
So, looking forward to patches.
On Wed, 27 Aug 2014 08:30:25 -0400
Greg Troxel <address@hidden> wrote:
>
> "Gary E. Miller" <address@hidden> writes:
>
> > As recently discused, TIOCMIWAIT is not in the RFC2783 path!
> >
> > just look at the code!
>
> I don't follow this at all. I am looking at ppsthread.c on git
> master, and specifically at gpsd_ppsmonitor().
>
> I see a loop which has ifdefs for TIOCMIWAIT, and then an ifdef for
> HAVE_SYS_TIMEPPS_H, and within that RFC2783 ifdef, further conditional
> behavior based on TIOCMIWAIT.
>
> Reading the code, I don't see how it copes with a system that doesn't
> have TIOCMIWAIT and doesn't implement waiting on time_pps_fetch, which
> is what I remember being the issue last November. I think what's
> needed is to delay for 100 ms or so when time_pps_fetch says no edge
> is available, and not to complain about that.
>
> The other issue is that there's a lot of sanity checking going on
> (towards the bottom of the function) which is currently conditional on
> TIOCMIWAIT, but really shouldn't be. I suspect that's something I did
> to ifdef out code that wouldn't build. It seems that obtaining
> timestamps of edges (via either mechanism) should be entirely
> separated From gpsd looking at those edge timestamps and deciding
> what it thinks about them.
>
> A final complexity is that with RFC2783, finding the header file
> doesn't imply that it will work, because on all systems we know
> about, it's an optional kernel feature. I think that's handled
> right. With TIOCMIWAIT, I don't know if there are systems that have
> the symbol defined in the .h file but don't implement it.
>
> I suspect that if you were to #undef TIOCMIWAIT on your gentoo system,
> the code would build but then probably won't work right. (I am
> guessing that Linux KPPS doesn't implement the optional CANWAIT
> facility, because ntpd doesn't use it and thus it wouldn't have
> helped make anything work.)
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
address@hidden Tel:+1(541)382-8588
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- Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. release-3.11-46-g6a33950, Gary E. Miller, 2014/08/26
- Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. release-3.11-46-g6a33950, Eric S. Raymond, 2014/08/26
- Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. release-3.11-46-g6a33950, Greg Troxel, 2014/08/27
- Re: [gpsd-dev] [gpsd-commit-watch] [SCM] GPSD branch, master, updated. release-3.11-46-g6a33950,
Gary E. Miller <=