[git commit] ntpd: increase minimum G.FREQHOLD_cnt from 8 to 10

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=029bd187bdad5bfd7771ed356e633e8ec8044d2e
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

With ~0.9 initiall offsets, using 8 results in a bit too eager
frequency correction.

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 networking/ntpd.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/networking/ntpd.c b/networking/ntpd.c
index a1b8ac5b0..7b800369e 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -149,6 +149,7 @@
  */
 
 #define INITIAL_SAMPLES    4    /* how many samples do we want for init */
+#define MIN_FREQHOLD      10    /* adjust offset, but not freq in this many first adjustments */
 #define BAD_DELAY_GROWTH   4    /* drop packet if its delay grew by more than this */
 
 #define RETRY_INTERVAL    32    /* on send/recv error, retry in N secs (need to be power of 2) */
@@ -1753,7 +1754,7 @@ update_local_clock(peer_t *p)
 //15:19:39.114 update from:<IP> offset:+0.327022 delay:0.158384 jitter:0.108538 clock drift:-1.393ppm tc:4
 //15:20:12.715 update from:<IP> offset:+0.275596 delay:0.158297 jitter:0.097292 clock drift:-1.393ppm tc:4
 //15:20:45.111 update from:<IP> offset:+0.225715 delay:0.158271 jitter:0.087841 clock drift:-1.393ppm tc:4
-// If allwed to continue, it would start increasing tmx.freq now.
+// If allowed to continue, it would start increasing tmx.freq now.
 // Instead, it was ^Ced, and started anew:
 //15:21:15.043 no valid datapoints, no peer selected
 //15:21:17.408 update from:<IP> offset:+0.175910 delay:0.158314 jitter:0.076683 clock drift:-1.393ppm tc:4
@@ -1776,9 +1777,9 @@ update_local_clock(peer_t *p)
 //15:31:53.473 update from:<IP> offset:+0.000007 delay:0.158142 jitter:0.010922 clock drift:+9.343ppm tc:6
 //15:32:58.902 update from:<IP> offset:-0.000728 delay:0.158222 jitter:0.009454 clock drift:+9.298ppm tc:6
 			/*
-			 * This expression would choose 15 in the above example.
+			 * This expression would choose MIN_FREQHOLD + 7 in the above example.
 			 */
-			G.FREQHOLD_cnt = 8 + ((unsigned)(abs(tmx.offset)) >> 16);
+			G.FREQHOLD_cnt = MIN_FREQHOLD + ((unsigned)(abs(tmx.offset)) >> 16);
 		}
 		G.FREQHOLD_cnt--;
 		tmx.status |= STA_FREQHOLD;