[PATCH 2/2 v3] adjtimex.2: add explanation on ADJ_TAI mode

From: Laurent Georget
Date: Sun Nov 30 2014 - 05:24:59 EST


This patch includes the adjtimex mode ADJ_TAI, intended to update the
TAI offset. There are other FIXMEs in the man page and it's a bit
outdated. I'll be on it once those first patches are accepted (to be
sure to do the right thing).

Thanks

Laurent

diff --git a/man2/adjtimex.2 b/man2/adjtimex.2
index 0b919c5..396b8cc 100644
--- a/man2/adjtimex.2
+++ b/man2/adjtimex.2
@@ -24,9 +24,7 @@
.\" Modified 1997-01-31 by Eric S. Raymond <esr@xxxxxxxxxxx>
.\" Modified 1997-07-30 by Paul Slootman <paul@xxxxxxxxxxxxxxx>
.\" Modified 2004-05-27 by Michael Kerrisk <mtk.manpages@xxxxxxxxx>
-.\"
-.\" FIXME Document ADJ_TAI (added in Linux 2.6.26)
-.\" commit 153b5d054ac2d98ea0d86504884326b6777f683d
+.\" Modified 2014-11-30 by Laurent Georget <laurent.georget@xxxxxxxxxx>
.\"
.\" FIXME Document ADJ_MICRO and ADJ_NANO (added in Linux 2.6.26)
.\" commit eea83d896e318bda54be2d2770d2c5d6668d11db
@@ -101,6 +99,7 @@ combination of zero or more of the following bits:
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
+#define ADJ_TAI 0x0080 /* TAI offset */
#define ADJ_TICK 0x4000 /* tick value */
#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime() */
.fi
@@ -110,6 +109,24 @@ Ordinary users are restricted to a zero value for
.IR modes .
Only the superuser may set any parameters.
.br
+In the case of
+.BR ADJ_TAI ,
+as
+.I buf->tai
+is read-only, the new value is passed through
+.IR buf->constant ,
+therefore
+.B ADJ_TIMECONST
+and
+.B ADJ_TAI
+should probably not be used at the same time.
+.PP
+Support for TAI (Atomic International Time, for a complete explanation
about
+what it is and what is the difference between TAI and UTC, see
+.UR http://www.bipm.org/en/bipm/tai/tai.html
+.I BIPM
+.UE )
+has been added in version 2.6.26.
.ne 12v
.SH RETURN VALUE
On success,
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