Bug 1933 - WWVB/Spectracom driver timestamps LFs, not CRs

bk: 4dd3021fc-hFvkEX2wp0QSoYil-BXg

diff --git a/ChangeLog b/ChangeLog
index b10ea7851bb925d5c13e469aa08de72d6cb81f9d..13dc235cfa3aae3ee65bb793b1149b315643b90e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,4 @@
+* [Bug 1933] WWVB/Spectracom driver timestamps LFs, not CRs.
 (4.2.7p168) 2011/05/16 Released by Harlan Stenn <stenn@ntp.org>
 * Convert receive buffer queue from doubly-linked list to FIFO.
 (4.2.7p167) 2011/05/14 Released by Harlan Stenn <stenn@ntp.org>

diff --git a/ntpd/refclock_wwvb.c b/ntpd/refclock_wwvb.c
index 39c75beb581119700b78c265ee110fcd2f6a1248..c9b3a34ae011af8c891c8f21b825133bdcf733c0 100644 (file)
--- a/ntpd/refclock_wwvb.c
+++ b/ntpd/refclock_wwvb.c
@@ -54,7 +54,7 @@
  *     hh:mm:ss = hours, minutes, seconds
  *     i = synchronization flag (' ' = in synch, '?' = out of synch)
  *
- * The alarm condition is indicated by other than ' ' at a, which occurs
+ * The alarm condition is indicated by other than ' ' at i, which occurs
  * during initial synchronization and when received signal is lost for
  * about ten hours.
  *
@@ -69,7 +69,7 @@
  *     ddd = day of year
  *     hh:mm:ss.fff = hours, minutes, seconds, milliseconds
  *
- * The alarm condition is indicated by other than ' ' at a, which occurs
+ * The alarm condition is indicated by other than ' ' at i, which occurs
  * during initial synchronization and when received signal is lost for
  * about ten hours. The unlock condition is indicated by other than ' '
  * at q.
@@ -120,9 +120,8 @@
 #define        DESCRIPTION     "Spectracom WWVB/GPS Receiver" /* WRU */
 
 #define        LENWWVB0        22      /* format 0 timecode length */
-#define LENWWVB1       22      /* format 1 timecode length */
 #define        LENWWVB2        24      /* format 2 timecode length */
-#define LENWWVB3        29      /* format 3 timecode length */
+#define LENWWVB3       29      /* format 3 timecode length */
 #define MONLIN         15      /* number of monitoring lines */
 
 /*
@@ -136,7 +135,8 @@ struct wwvbunit {
        int     tcount;         /* timecode sample counter */
        int     pcount;         /* PPS sample counter */
 #endif /* HAVE_PPSAPI */
-       l_fp    laststamp;      /* last receive timestamp */
+       l_fp    laststamp;      /* last <CR> timestamp */
+       int     prev_eol_cr;    /* was last EOL <CR> (not <LF>)? */
        u_char  lasthour;       /* last hour (for monitor) */
        u_char  linect;         /* count ignored lines (for monitor */
 };
@@ -249,6 +249,7 @@ wwvb_receive(
        struct recvbuf *rbufp
        )
 {
+       const l_fp one_char_time = { { 0 }, { (u_int32)(FRAC / 960) } };
        struct wwvbunit *up;
        struct refclockproc *pp;
        struct peer *peer;
@@ -280,13 +281,43 @@ wwvb_receive(
         * reading precision is only to the millisecond. Thus, unless
         * you have a PPS gadget and don't have to have the year, format
         * 0 provides the lowest jitter.
+        * Save the timestamp of each <CR> in up->laststamp.  Lines with
+        * no characters occur for every <LF>, and for some <CR>s when
+        * format 0 is used. Format 0 starts and ends each cycle with a
+        * <CR><LF> pair, format 2 starts each cycle with its only pair.
+        * The preceding <CR> is the on-time character for both formats.
+        * The timestamp provided with non-empty lines corresponds to
+        * the <CR> following the timecode, which is ultimately not used
+        * with format 0 and is used for the following timecode for
+        * format 2.
         */
        if (temp == 0) {
-               up->laststamp = trtmp;
+               if (up->prev_eol_cr) {
+                       DPRINTF(2, ("wwvb: <LF> @ %s\n",
+                                   prettydate(&trtmp)));
+               } else {
+                       up->laststamp = trtmp;
+                       DPRINTF(2, ("wwvb: <CR> @ %s\n", 
+                                   prettydate(&trtmp)));
+               }
+               up->prev_eol_cr = !up->prev_eol_cr;
                return;
        }
        pp->lencode = temp;
        pp->lastrec = up->laststamp;
+       up->laststamp = trtmp;
+       up->prev_eol_cr = TRUE;
+       DPRINTF(2, ("wwvb: code @ %s\n"
+                   "       using %s minus one char\n",
+                   prettydate(&trtmp), prettydate(&pp->lastrec)));
+       if (L_ISZERO(&pp->lastrec))
+               return;
+
+       /*
+        * The start of the <CR> is the on-time event, while our
+        * timestamp reflects the end of that <CR> at best. Adjust.
+        */
+       L_SUB(&pp->lastrec, &one_char_time);
 
        /*
         * We get down to business, check the timecode format and decode
@@ -306,9 +337,11 @@ wwvb_receive(
                if (sscanf(pp->a_lastcode,
                    "%c %3d %2d:%2d:%2d%c%cTZ=%2d",
                    &syncchar, &pp->day, &pp->hour, &pp->minute,
-                   &pp->second, &tmpchar, &dstchar, &tz) == 8)
+                   &pp->second, &tmpchar, &dstchar, &tz) == 8) {
                        pp->nsec = 0;
                        break;
+               }
+               goto bad_format;
 
        case LENWWVB2:
 
@@ -318,14 +351,19 @@ wwvb_receive(
                    "%c%c %2d %3d %2d:%2d:%2d.%3ld %c",
                    &syncchar, &qualchar, &pp->year, &pp->day,
                    &pp->hour, &pp->minute, &pp->second, &pp->nsec,
-                   &leapchar) == 9)
+                   &leapchar) == 9) {
                        pp->nsec *= 1000000;
                        break;
+               }
+               goto bad_format;
 
        case LENWWVB3:
 
-               /*
+               /*
                 * Timecode format 3: "0003I yyyymmdd hhmmss+0000SL#"
+                * WARNING: Undocumented, and the on-time character # is
+                * not yet handled correctly by this driver.  It may be
+                * as simple as compensating for an additional 1/960 s.
                 */
                if (sscanf(pp->a_lastcode,
                    "0003%c %4d%2d%2d %2d%2d%2d+0000%c%c",
@@ -336,8 +374,10 @@ wwvb_receive(
                        pp->nsec = 0;
                        break;
                }
+               goto bad_format;
 
        default:
+       bad_format:
 
                /*
                 * Unknown format: If dumping internal table, record