Alexander Gordeev 025b40abe7 ntp: add hardpps implementation ... This commit adds hardpps() implementation based upon the original one from the NTPv4 reference kernel code from David Mills. However, it is highly optimized towards very fast syncronization and maximum stickness to PPS signal. The typical error is less then a microsecond. To make it sync faster I had to throw away exponential phase filter so that the full phase offset is corrected immediately. Then I also had to throw away median phase filter because it gives a bigger error itself if used without exponential filter. Maybe we will find an appropriate filtering scheme in the future but it's not necessary if the signal quality is ok. Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2011-01-13 08:03:20 -08:00
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clients	pps: timestamp is always passed to dcd_change()	2011-01-13 08:03:20 -08:00
Kconfig	ntp: add hardpps implementation	2011-01-13 08:03:20 -08:00
Makefile	pps: LinuxPPS clients support	2010-03-12 15:52:43 -08:00
kapi.c	pps: simplify conditions a bit	2011-01-13 08:03:20 -08:00
pps.c	pps: make idr lock a mutex and protect idr_pre_get	2011-01-13 08:03:20 -08:00
sysfs.c	LinuxPPS: core support	2009-06-18 13:04:04 -07:00