sched/hrtimer: fix hrtimer regression introduced by recent update and add support for tickless with hrtimer

include/nuttx/arch.h

@@ -2051,8 +2051,8 @@ int up_alarm_tick_cancel(FAR clock_t *ticks);
  *
  ****************************************************************************/
 
-#if defined(CONFIG_HRTIMER) || \
-    defined(CONFIG_SCHED_TICKLESS) && defined(CONFIG_SCHED_TICKLESS_ALARM)
+#if (defined(CONFIG_HRTIMER) && defined(CONFIG_ALARM_ARCH)) || \
+    (defined(CONFIG_SCHED_TICKLESS) && defined(CONFIG_SCHED_TICKLESS_ALARM))
 int up_alarm_start(FAR const struct timespec *ts);
 int up_alarm_tick_start(clock_t ticks);
 #endif
@@ -2123,7 +2123,8 @@ int up_timer_tick_cancel(FAR clock_t *ticks);
  *
  ****************************************************************************/
 
-#if defined(CONFIG_SCHED_TICKLESS) && !defined(CONFIG_SCHED_TICKLESS_ALARM)
+#if (defined(CONFIG_HRTIMER) && defined(CONFIG_TIMER_ARCH)) || \
+    (defined(CONFIG_SCHED_TICKLESS) && !defined(CONFIG_SCHED_TICKLESS_ALARM))
 int up_timer_start(FAR const struct timespec *ts);
 int up_timer_tick_start(clock_t ticks);
 #endif

sched/hrtimer/hrtimer.h

@@ -122,26 +122,29 @@ void hrtimer_process(uint64_t now);
  *   ns - Expiration time in nanoseconds.
  *
  * Returned Value:
- *   OK (0) on success, negated errno on failure.
+ *   None.
+ *
+ * Assumptions:
+ *   The underlying timer start function returns 0 on success.
  ****************************************************************************/
 
 static inline_function void hrtimer_reprogram(uint64_t next_expired)
 {
-#ifdef CONFIG_SCHED_TICKLESS
-  int ret;
+  int ret = 0;
   struct timespec ts;
-#  ifdef CONFIG_SCHED_TICKLESS_ALARM
+
   clock_nsec2time(&ts, next_expired);
+
+#ifdef CONFIG_ALARM_ARCH
   ret = up_alarm_start(&ts);
-#  else
+#else
   struct timespec current;
   up_timer_gettime(&current);
-  clock_nsec2time(&ts, next_expired);
   clock_timespec_subtract(&ts, &current, &ts);
   ret = up_timer_start(&ts);
-#  endif
-  DEBUGASSERT(ret == 0);
 #endif
+
+  DEBUGASSERT(ret == 0);
 }
 
 /****************************************************************************

sched/sched/sched.h

@@ -309,6 +309,10 @@ extern volatile spinlock_t g_cpu_tasklistlock;
 
 void nxsched_process_tick(void);
 
+#if defined(CONFIG_HRTIMER) && defined(CONFIG_SCHED_TICKLESS)
+int nxsched_hrtimer_tick_start(clock_t tick);
+#endif
+
 int nxthread_create(FAR const char *name, uint8_t ttype, int priority,
                     FAR void *stack_addr, int stack_size, main_t entry,
                     FAR char * const argv[], FAR char * const envp[]);

sched/sched/sched_timer.c

@@ -108,6 +108,16 @@ nxsched_hrtimer_callback(FAR const struct hrtimer_s *hrtimer,
  * Public Functions
  ****************************************************************************/
 
+#if defined(CONFIG_HRTIMER) && defined(CONFIG_SCHED_TICKLESS)
+int nxsched_hrtimer_tick_start(clock_t tick)
+{
+  return hrtimer_start(&g_sched_hrtimer,
+                       nxsched_hrtimer_callback,
+                       tick * NSEC_PER_TICK,
+                       HRTIMER_MODE_ABS);
+}
+#endif
+
 /****************************************************************************
  * Name: nxsched_process_timer
  *

sched/wdog/wdog.h

@@ -114,12 +114,16 @@ static inline_function clock_t wd_adjust_next_tick(clock_t tick)
 static inline_function void wd_timer_start(clock_t tick)
 {
   clock_t next_tick = wd_adjust_next_tick(tick);
-#ifdef CONFIG_SCHED_TICKLESS_ALARM
+
+#ifdef CONFIG_HRTIMER
+  nxsched_hrtimer_tick_start(tick);
+#elif defined(CONFIG_SCHED_TICKLESS_ALARM)
   up_alarm_tick_start(next_tick);
 #else
   up_timer_tick_start(next_tick - clock_systime_ticks());
 #endif
 }
+
 static inline_function void wd_timer_cancel(void)
 {
   struct timespec ts;