tsproc: Track the validity of the filtered delay explicitly.

We will want to test whether a valid filtered delay value has been
calculated or not.  However, we cannot simply test for zero since that is
a legitimate possible delay value.  This patch adds a flag that reflects
the state of the filtered delay field.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/tsproc.c b/tsproc.c
index cf5f0dc..1eb24a1 100644
--- a/tsproc.c
+++ b/tsproc.c
@@ -42,6 +42,7 @@ struct tsproc {
 
         /* Current filtered delay */
         tmv_t filtered_delay;
+        int filtered_delay_valid;
 
         /* Delay filter */
         struct filter *delay_filter;
@@ -115,6 +116,7 @@ void tsproc_set_clock_rate_ratio(struct tsproc *tsp, double clock_rate_ratio)
 void tsproc_set_delay(struct tsproc *tsp, tmv_t delay)
 {
         tsp->filtered_delay = delay;
+        tsp->filtered_delay_valid = 1;
 }
 
 tmv_t get_raw_delay(struct tsproc *tsp)
@@ -149,6 +151,7 @@ int tsproc_update_delay(struct tsproc *tsp, tmv_t *delay)
 
         raw_delay = get_raw_delay(tsp);
         tsp->filtered_delay = filter_sample(tsp->delay_filter, raw_delay);
+        tsp->filtered_delay_valid = 1;
 
         pr_debug("delay   filtered %10" PRId64 "   raw %10" PRId64,
                  tsp->filtered_delay, raw_delay);
@@ -199,5 +202,6 @@ void tsproc_reset(struct tsproc *tsp, int full)
         if (full) {
                 tsp->clock_rate_ratio = 1.0;
                 filter_reset(tsp->delay_filter);
+                tsp->filtered_delay_valid = 0;
         }
 }