diff options
| -rw-r--r-- | src/sam3x8e/timer.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/src/sam3x8e/timer.c b/src/sam3x8e/timer.c index e473be9f..ead9c90f 100644 --- a/src/sam3x8e/timer.c +++ b/src/sam3x8e/timer.c @@ -89,12 +89,12 @@ timer_set_next(uint32_t next) return 1; } -static uint32_t timer_repeat; -#define TIMER_MAX_REPEAT 400 -#define TIMER_MAX_NEXT_REPEAT 150 +static uint32_t timer_repeat_until; +#define TIMER_IDLE_REPEAT_TICKS timer_from_us(500) +#define TIMER_REPEAT_TICKS timer_from_us(100) #define TIMER_MIN_TRY_TICKS timer_from_us(1) -#define TIMER_DEFER_REPEAT_TICKS timer_from_us(2) +#define TIMER_DEFER_REPEAT_TICKS timer_from_us(5) // Similar to timer_set_next(), but wait for the given time if it is // in the near future. @@ -108,10 +108,9 @@ timer_try_set_next(uint32_t next) goto done; // Next timer is in the past or near future - can't reschedule to it - uint32_t tr = timer_repeat-1; - if (likely(tr)) { + if (likely(sched_is_before(now, timer_repeat_until))) { + // Can run more timers from this irq; briefly allow irqs irq_enable(); - timer_repeat = tr; while (diff >= 0) { // Next timer is in the near future - wait for time to occur now = timer_read_time(); @@ -120,12 +119,12 @@ timer_try_set_next(uint32_t next) irq_disable(); return 0; } + if (diff < (int32_t)(-timer_from_us(1000))) + goto fail; // Too many repeat timers from a single interrupt - force a pause - timer_repeat = TIMER_MAX_NEXT_REPEAT; + timer_repeat_until = now + TIMER_REPEAT_TICKS; next = now + TIMER_DEFER_REPEAT_TICKS; - if (diff < (int32_t)(-timer_from_us(1000))) - goto fail; done: timer_set(next); @@ -134,9 +133,13 @@ fail: shutdown("Rescheduled timer in the past"); } +// Periodic background task that temporarily boosts priority of +// timers. This helps prioritize timers when tasks are idling. static void timer_task(void) { - timer_repeat = TIMER_MAX_REPEAT; + irq_disable(); + timer_repeat_until = timer_read_time() + TIMER_IDLE_REPEAT_TICKS; + irq_enable(); } DECL_TASK(timer_task); |