ntpd: fix a case when discipline_jitter = 0 if we step

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 17 deletions

diff --git a/networking/ntpd.c b/networking/ntpd.c
index b0bfe440f..e9805087c 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -340,7 +340,10 @@ struct globals {
         double   last_update_offset;    // c.last
         double   last_update_recv_time; // s.t
         double   discipline_jitter;     // c.jitter
-        double   offset_to_jitter_ratio;
+        /* Since we only compare it with ints, can simplify code
+         * by not making this variable floating point:
+         */
+        unsigned offset_to_jitter_ratio;
         //double   cluster_offset;        // s.offset
         //double   cluster_jitter;        // s.jitter
 #if !USING_KERNEL_PLL_LOOP
@@ -1339,7 +1342,7 @@ update_local_clock(peer_t *p)
                         return 1; /* "ok to increase poll interval" */
                 }
 #endif
-                offset = 0;
+                abs_offset = offset = 0;
                 set_new_values(STATE_SYNC, offset, recv_time);
 
         } else { /* abs_offset <= STEP_THRESHOLD */
@@ -1356,10 +1359,6 @@ update_local_clock(peer_t *p)
                 etemp = SQUARE(G.discipline_jitter);
                 dtemp = SQUARE(offset - G.last_update_offset);
                 G.discipline_jitter = SQRT(etemp + (dtemp - etemp) / AVG);
-                if (G.discipline_jitter < G_precision_sec)
-                        G.discipline_jitter = G_precision_sec;
-                G.offset_to_jitter_ratio = fabs(offset) / G.discipline_jitter;
-                VERB3 bb_error_msg("discipline jitter=%f", G.discipline_jitter);
 
                 switch (G.discipline_state) {
                 case STATE_NSET:
@@ -1436,6 +1435,10 @@ update_local_clock(peer_t *p)
                 }
         }
 
+        if (G.discipline_jitter < G_precision_sec)
+                G.discipline_jitter = G_precision_sec;
+        G.offset_to_jitter_ratio = abs_offset / G.discipline_jitter;
+
         G.reftime = G.cur_time;
         G.ntp_status = p->lastpkt_status;
         G.refid = p->lastpkt_refid;
@@ -1473,7 +1476,7 @@ update_local_clock(peer_t *p)
                 memset(&tmx, 0, sizeof(tmx));
                 if (adjtimex(&tmx) < 0)
                         bb_perror_msg_and_die("adjtimex");
-                VERB3 bb_error_msg("p adjtimex freq:%ld offset:%+ld constant:%ld status:0x%x",
+                bb_error_msg("p adjtimex freq:%ld offset:%+ld constant:%ld status:0x%x",
                                 tmx.freq, tmx.offset, tmx.constant, tmx.status);
         }
 
@@ -1506,7 +1509,7 @@ update_local_clock(peer_t *p)
          * To be on a safe side, let's do it only if offset is significantly
          * larger than jitter.
          */
-        if (tmx.constant > 0 && G.offset_to_jitter_ratio > TIMECONST_HACK_GATE)
+        if (tmx.constant > 0 && G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE)
                 tmx.constant--;
 
         //tmx.esterror = (uint32_t)(clock_jitter * 1e6);
@@ -1520,7 +1523,7 @@ update_local_clock(peer_t *p)
         VERB3 bb_error_msg("adjtimex:%d freq:%ld offset:%+ld status:0x%x",
                                 rc, tmx.freq, tmx.offset, tmx.status);
         G.kernel_freq_drift = tmx.freq / 65536;
-        VERB2 bb_error_msg("update peer:%s, offset:%+f, jitter:%f, clock drift:%+.3f ppm, tc:%d",
+        VERB2 bb_error_msg("update from:%s offset:%+f jitter:%f clock drift:%+.3fppm tc:%d",
                         p->p_dotted, offset, G.discipline_jitter, (double)tmx.freq / 65536, (int)tmx.constant);
 
         return 1; /* "ok to increase poll interval" */
@@ -1705,14 +1708,7 @@ recv_and_process_peer_pkt(peer_t *p)
                  * is increased, otherwise it is decreased. A bit of hysteresis
                  * helps calm the dance. Works best using burst mode.
                  */
-                VERB4 if (rc > 0) {
-                        bb_error_msg("offset:%+f POLLADJ_GATE*discipline_jitter:%f poll:%s",
-                                q->filter_offset, POLLADJ_GATE * G.discipline_jitter,
-                                fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter
-                                        ? "grows" : "falls"
-                        );
-                }
-                if (rc > 0 && G.offset_to_jitter_ratio < POLLADJ_GATE) {
+                if (rc > 0 && G.offset_to_jitter_ratio <= POLLADJ_GATE) {
                         /* was += G.poll_exp but it is a bit
                          * too optimistic for my taste at high poll_exp's */
                         G.polladj_count += MINPOLL;