From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Thu, 24 Feb 2022 07:45:10 +0000 (+0100)
Subject: refclock: trim offset in local mode
X-Git-Tag: 4.3-pre1~54
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=55717c1ccdf75aaa7b30570ac3478237a66a89f1;p=thirdparty%2Fchrony.git

refclock: trim offset in local mode

With the local option, trim offset larger than 1 second to not lose
precision after large steps of the clock.
---

diff --git a/refclock.c b/refclock.c
index cfa958ca..42acd53c 100644
--- a/refclock.c
+++ b/refclock.c
@@ -757,6 +757,12 @@ follow_local(RCL_Instance inst, struct timespec *prev_ref_time, double prev_freq
   LCL_ReadCookedTime(&now, NULL);
   SST_SlewSamples(stats, &now, dfreq, doffset);
   SPF_SlewSamples(inst->filter, &now, dfreq, doffset);
+
+  /* Keep the offset close to zero to not lose precision */
+  if (fabs(offset) >= 1.0) {
+    SST_CorrectOffset(stats, -round(offset));
+    SPF_CorrectOffset(inst->filter, -round(offset));
+  }
 }
 
 static void