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xtimer: fix error (turn around and current time update)
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Hyungsin committed Nov 20, 2017
1 parent ea14350 commit 23c64b0
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Showing 2 changed files with 38 additions and 40 deletions.
6 changes: 2 additions & 4 deletions sys/include/xtimer/implementation.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,7 @@ static inline uint32_t _xtimer_now(void)
return latched_high_cnt | now;
#else
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
uint32_t diff_s;
uint64_t diff_s;
uint32_t now_s;

do {
Expand All @@ -135,9 +135,7 @@ static inline uint32_t _xtimer_now(void)
}
} while (diff_s < STIMER_HZ/XTIMER_HZ);

prev_x += diff_s*XTIMER_HZ/STIMER_HZ;
prev_s = now_s;
return prev_x;
return _xtimer_lltimer_mask(prev_x + (uint32_t)(diff_s*XTIMER_HZ/STIMER_HZ));
#else
return _xtimer_lltimer_now();
#endif
Expand Down
72 changes: 36 additions & 36 deletions sys/xtimer/xtimer_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,6 @@ volatile uint32_t _xtimer_high_cnt = 0;
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
volatile uint32_t prev_s = 0xffffffff;
volatile uint32_t prev_x = 0xffffffff;
bool init = false;
#endif

static inline void xtimer_spin_until(uint32_t value);
Expand Down Expand Up @@ -72,8 +71,8 @@ static inline void xtimer_spin_until(uint32_t target) {
while (_xtimer_lltimer_now() > target);
while (_xtimer_lltimer_now() < target);
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = _xtimer_lltimer_now();
prev_s = _stimer_lltimer_now();
prev_x = _xtimer_lltimer_now();
#endif
}

Expand All @@ -87,8 +86,8 @@ void xtimer_init(void)
* STIMER must be faster than XTIMER (e.g., 8 MHz or 48 MHz).
*/
timer_init(STIMER_DEV, STIMER_HZ, _periph_timer_callback, NULL);
prev_x = _xtimer_lltimer_now();
prev_s = _stimer_lltimer_now();
prev_x = _xtimer_lltimer_now();
#endif
/* register initial overflow tick */
_lltimer_set(0xFFFFFFFF);
Expand Down Expand Up @@ -172,20 +171,9 @@ void _xtimer_set(xtimer_t *timer, uint32_t offset)
_shoot(timer);
}
else {
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
if (!init) {
prev_x = _xtimer_lltimer_now();
prev_s = _stimer_lltimer_now();
init = true;
}
prev_x = _xtimer_now();
uint32_t target = prev_x + offset;
_xtimer_set_absolute(timer, target, prev_x);
#else
uint32_t now = _xtimer_now();
uint32_t target = now + offset;
_xtimer_set_absolute(timer, target, now);
#endif
}
}

Expand Down Expand Up @@ -241,11 +229,17 @@ int _xtimer_set_absolute(xtimer_t *timer, uint32_t target, uint32_t now)
if ( (timer->long_target > _long_cnt) || !_this_high_period(target) ) {
DEBUG("xtimer_set_absolute(): the timer doesn't fit into the low-level timer's mask.\n");
_add_timer_to_long_list(&long_list_head, timer);
if (!timer_list_head) {
_lltimer_set(0xFFFFFFFF);
}
}
else {
if (_xtimer_lltimer_mask(now) >= target) {
DEBUG("xtimer_set_absolute(): the timer will expire in the next timer period\n");
_add_timer_to_list(&overflow_list_head, timer);
if (!timer_list_head) {
_lltimer_set(0xFFFFFFFF);
}
}
else {
DEBUG("timer_set_absolute(): timer will expire in this timer period.\n");
Expand Down Expand Up @@ -499,24 +493,27 @@ static void _timer_callback(void)

/* make sure the timer counter also arrived
* in the next timer period */
while (_xtimer_lltimer_now() == _xtimer_lltimer_mask(0xFFFFFFFF)) {}
while ((reference = _xtimer_lltimer_now()) == _xtimer_lltimer_mask(0xFFFFFFFF)) {}
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
}
else {
/* we ended up in _timer_callback and there is
* a timer waiting.
*/
/* set our period reference to the current time. */
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
reference = _xtimer_lltimer_now();
}
now = reference;
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = now;
#endif
overflow:
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif

overflow:
/* check if next timers are close to expiring */
while (timer_list_head && (_time_left(_xtimer_lltimer_mask(timer_list_head->target), reference, now) < XTIMER_ISR_BACKOFF)) {
/* make sure we don't fire too early */
Expand All @@ -527,9 +524,7 @@ static void _timer_callback(void)
now_s = _stimer_lltimer_now();
diff_s = _stimer_diff(prev_s, now_s);
} while (diff_s < STIMER_HZ/XTIMER_HZ);
now = now + diff_s*XTIMER_HZ/STIMER_HZ;
prev_x = now;
prev_s = now_s;
now = now + (uint32_t)((uint64_t)diff_s*XTIMER_HZ/STIMER_HZ);
#else
now = _xtimer_lltimer_now();
#endif
Expand All @@ -553,9 +548,7 @@ static void _timer_callback(void)
now_s = _stimer_lltimer_now();
diff_s = _stimer_diff(prev_s, now_s);
if (diff_s >= STIMER_HZ/XTIMER_HZ) {
now = now + diff_s*XTIMER_HZ/STIMER_HZ;
prev_x = now;
prev_s = now_s;
now = now + (uint32_t)((uint64_t)diff_s*XTIMER_HZ/STIMER_HZ);
}
#else
now = _xtimer_lltimer_now();
Expand All @@ -571,6 +564,9 @@ static void _timer_callback(void)
timer_list_head != NULL);
_next_period();
reference = 0;
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
now = _xtimer_lltimer_now();
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = now;
Expand All @@ -584,6 +580,9 @@ static void _timer_callback(void)

/* make sure we're not setting a time in the past */
if (next_target < (now + XTIMER_ISR_BACKOFF)) {
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
now = _xtimer_lltimer_now();
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = now;
Expand All @@ -595,23 +594,23 @@ static void _timer_callback(void)
/* set low level timer */
_lltimer_set(next_target);
}
else if (overflow_list_head != NULL) {
else {
/* there's no timer planned for this timer period */
/* schedule callback on next overflow */
next_target = _xtimer_lltimer_mask(0xFFFFFFFF);

/* update current time */
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
now_s = _stimer_lltimer_now();
diff_s = _stimer_diff(prev_s, now_s);
now = now + diff_s*XTIMER_HZ/STIMER_HZ;
now = now + (uint32_t)((uint64_t)diff_s*XTIMER_HZ/STIMER_HZ);
#else
now = _xtimer_lltimer_now();
#endif
/* check for overflow again */
if (now < reference) {
_next_period();
reference = 0;
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
now = _xtimer_lltimer_now();
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = now;
Expand All @@ -625,6 +624,9 @@ static void _timer_callback(void)
while (_xtimer_lltimer_now() >= now) {}
_next_period();
reference = 0;
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_s = _stimer_lltimer_now();
#endif
now = _xtimer_lltimer_now();
#if (XTIMER_HZ < 1000000ul) && (STIMER_HZ >= 1000000ul)
prev_x = now;
Expand All @@ -634,11 +636,9 @@ static void _timer_callback(void)
}
_in_handler = 0;

/* set low level timer */
_lltimer_set(next_target);
} else {
/* No need to set any timer */
_in_handler = 0;
if (overflow_list_head || long_list_head) {
/* schedule callback on next overflow */
_lltimer_set(0xFFFFFFFF);
}
}

}

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