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

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

diff --git a/networking/ntpd.c b/networking/ntpd.c
index b0bfe440f28e4fdca8277206494c1b69b0fee21c..e9805087c339a5f898f2e44b178762586e8b4ea3 100644 (file)
--- 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;