patch for NTP PPS support updated

Ulrich Windl (ulrich.windl@rz.uni-regensburg.de)
Wed, 23 Oct 1996 08:28:03 +0200


Hello,

Before I for get to mention the FTP address again, I'm telling you
that an updated version of my PPS patch is located on
pcphy4.physik.uni-regensburg.de in /pub/wiu09524/PPS/design.txt.

The previous path still works, but is a symbolic link now. The new
version is about 30kB, but is also available gzipped. In case you
have problems with the new patch, the old patch is still available
with the date suffix.

OK, now, what's new? Well almost nothing; the patch is just almost
complete now. It includes my EMail address as a patch to the CREDITS
file and the new proposed Documentation/Kernel-time.txt. Also the
cycle counting is default off now so that no additional messages are
produced in the syslog (they weren't many anyway). So far nobody
ailing me complained about severe problems, except about electrical
issues how to connect an arbitrary source to the carrier detect pin.

So far the god news. Now the bad thing: Currently the PPS interrupt
is edge-triggered, but unfortunately on both edges! Thanks for Ted
for remembering me of the fact that an interrupt is generated on any
level change. Obviously the existing code can already cope with that
kind of noise, but definitely I'll have to work on a mechanism to
allow only _one_ edge to call hardware_pps(). Up to now I have not
decided whether to make it configurable at runtime, or at compilation
time. Of course, I'd prefer runtime, but we'll have to pass the
parameter in some way. Suggestions?

Ulrich
(I'll be away from work tomorrow, thus no replies)