Patch for app_timer.c

app_timer.patch

diff --git i/nordic_sdk/libraries/timer/app_timer.c w/nordic_sdk/libraries/timer/app_timer.c
index 9dfcd284..e641c779 100755
--- i/nordic_sdk/libraries/timer/app_timer.c
+++ w/nordic_sdk/libraries/timer/app_timer.c
@@ -368,6 +368,7 @@ static void timer_timeouts_check(void)
     {
         timer_node_t *  p_timer;
         timer_node_t *  p_previous_timer;
+        uint32_t        total_ticks_elapsed;
         uint32_t        ticks_elapsed;
         uint32_t        ticks_expired;
 
@@ -375,7 +376,8 @@ static void timer_timeouts_check(void)
         ticks_expired = 0;
 
         // ticks_elapsed is collected here, job will use it.
-        ticks_elapsed = ticks_diff_get(rtc1_counter_get(), m_ticks_latest);
+        total_ticks_elapsed = ticks_diff_get(rtc1_counter_get(), m_ticks_latest);
+        ticks_elapsed = total_ticks_elapsed;
 
         // Auto variable containing the head of timers expiring.
         p_timer = mp_timer_id_head;
@@ -422,7 +424,7 @@ static void timer_timeouts_check(void)
         }
 
         // Queue the ticks expired.
-        m_ticks_elapsed[m_ticks_elapsed_q_write_ind] = ticks_expired;
+        m_ticks_elapsed[m_ticks_elapsed_q_write_ind] = total_ticks_elapsed;
 
         timer_list_handler_sched();
     }
@@ -432,10 +434,8 @@ static void timer_timeouts_check(void)
 /**@brief Function for acquiring the number of ticks elapsed.
  *
  * @param[out] p_ticks_elapsed   Number of ticks elapsed.
- *
- * @return     TRUE if elapsed ticks was read from queue, FALSE otherwise.
  */
-static bool elapsed_ticks_acquire(uint32_t * p_ticks_elapsed)
+static void elapsed_ticks_acquire(uint32_t * p_ticks_elapsed)
 {
     // Pick the elapsed value from queue.
     if (m_ticks_elapsed_q_read_ind != m_ticks_elapsed_q_write_ind)
@@ -448,18 +448,17 @@ static bool elapsed_ticks_acquire(uint32_t * p_ticks_elapsed)
         }
 
         *p_ticks_elapsed = m_ticks_elapsed[m_ticks_elapsed_q_read_ind];
-
-        m_ticks_latest += *p_ticks_elapsed;
-        m_ticks_latest &= MAX_RTC_COUNTER_VAL;
-
-        return true;
+        m_ticks_elapsed[m_ticks_elapsed_q_read_ind] = 0;
     }
     else
     {
-        // No elapsed value in queue.
-        *p_ticks_elapsed = 0;
-        return false;
+        // No elapsed value in queue. Make sure that the elapsed count is up to date even if nothing
+        // has expired in a while.
+        *p_ticks_elapsed = ticks_diff_get(rtc1_counter_get(), m_ticks_latest);
     }
+
+    m_ticks_latest += *p_ticks_elapsed;
+    m_ticks_latest &= MAX_RTC_COUNTER_VAL;
 }
 
 
@@ -527,13 +526,19 @@ static bool list_deletions_handler(void)
  * @param[in]  ticks_elapsed         Number of elapsed ticks.
  * @param[in]  ticks_previous        Previous known value of the RTC counter.
  * @param[out] p_restart_list_head   List of repeating timers to be restarted.
+ *
+ * @return     TRUE if Capture Compare register must be updated, FALSE otherwise.
  */
-static void expired_timers_handler(uint32_t         ticks_elapsed,
+static bool expired_timers_handler(uint32_t         ticks_elapsed,
                                    uint32_t         ticks_previous,
                                    timer_node_t **  p_restart_list_head)
 {
+    timer_node_t * p_timer_id_old_head;
     uint32_t ticks_expired = 0;
 
+    // Remember the old head, so as to decide if new compare needs to be set.
+    p_timer_id_old_head = mp_timer_id_head;
+
     while (mp_timer_id_head != NULL)
     {
         timer_node_t * p_timer;
@@ -569,6 +574,8 @@ static void expired_timers_handler(uint32_t         ticks_elapsed,
             *p_restart_list_head          = p_timer_expired;
         }
     }
+
+    return (mp_timer_id_head != p_timer_id_old_head);
 }
 
 
@@ -725,7 +732,6 @@ static void timer_list_handler(void)
 
     uint32_t       ticks_elapsed;
     uint32_t       ticks_previous;
-    bool           ticks_have_elapsed;
     bool           compare_update;
     timer_node_t * p_timer_id_head_old;
     
@@ -734,15 +740,14 @@ static void timer_list_handler(void)
     p_timer_id_head_old = mp_timer_id_head;
     
     // Get number of elapsed ticks
-    ticks_have_elapsed = elapsed_ticks_acquire(&ticks_elapsed);
+    elapsed_ticks_acquire(&ticks_elapsed);
 
     // Handle list deletions
     compare_update = list_deletions_handler();
     
     // Handle expired timers
-    if (ticks_have_elapsed)
+    if (expired_timers_handler(ticks_elapsed, ticks_previous, &p_restart_list_head))
     {
-        expired_timers_handler(ticks_elapsed, ticks_previous, &p_restart_list_head);
         compare_update = true;
     }