[PATCH] ntp: convert time_freq to nsec value

This converts time_freq to a scaled nsec value and adds around 6bit of extra
resolution.  This pushes the time_freq to its 32bit limits so the calculatons
have to be done with 64bit.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Roman Zippel 2006-09-30 23:28:27 -07:00 committed by Linus Torvalds
parent 97eebe138c
commit 04b617e71e
2 changed files with 24 additions and 14 deletions

View file

@ -91,10 +91,12 @@
#define SHIFT_SCALE 22 /* phase scale (shift) */
#define SHIFT_UPDATE (SHIFT_HZ + 1) /* time offset scale (shift) */
#define SHIFT_USEC 16 /* frequency offset scale (shift) */
#define SHIFT_NSEC 12 /* kernel frequency offset scale */
#define FINENSEC (1L << (SHIFT_SCALE - 10)) /* ~1 ns in phase units */
#define MAXPHASE 512000L /* max phase error (us) */
#define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
#define MAXFREQ_NSEC (512000L << SHIFT_NSEC) /* max frequency error (ppb) */
#define MINSEC 16L /* min interval between updates (s) */
#define MAXSEC 1200L /* max interval between updates (s) */
#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */