[PATCH v2 1/2] cyclic: Fix rollover every 72 min on 32 bits platforms
Patrice Chotard
patrice.chotard at foss.st.com
Tue Jan 14 14:28:13 CET 2025
On 32 bits platforms, timer_get_us() returns an unsigned long which
is a 32 bits. timer_get_us() wraps around every 72 minutes
(2 ^ 32 / 1000000 =~ 4295 sec =~ 72 min).
So the test "if time_after_eq64(now, cyclic->next_call)" is no more
true when cyclic->next_call becomes above 32 bits max value (4294967295).
At this point after 72 min, no more cyclic function are
executed included watchdog one.
Instead of using timer_get_us(), use get_timer_us() which returns a
uint64_t, this allows a rollover every 584942 years.
Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
---
Changes in v2:
_ Replace remaining timer_get_us() by get_timer_us(0)
common/cyclic.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/common/cyclic.c b/common/cyclic.c
index 196797fd61e..fad071a39c6 100644
--- a/common/cyclic.c
+++ b/common/cyclic.c
@@ -36,7 +36,7 @@ void cyclic_register(struct cyclic_info *cyclic, cyclic_func_t func,
cyclic->func = func;
cyclic->name = name;
cyclic->delay_us = delay_us;
- cyclic->start_time_us = timer_get_us();
+ cyclic->start_time_us = get_timer_us(0);
hlist_add_head(&cyclic->list, cyclic_get_list());
}
@@ -61,13 +61,13 @@ static void cyclic_run(void)
* Check if this cyclic function needs to get called, e.g.
* do not call the cyclic func too often
*/
- now = timer_get_us();
+ now = get_timer_us(0);
if (time_after_eq64(now, cyclic->next_call)) {
/* Call cyclic function and account it's cpu-time */
cyclic->next_call = now + cyclic->delay_us;
cyclic->func(cyclic);
cyclic->run_cnt++;
- cpu_time = timer_get_us() - now;
+ cpu_time = get_timer_us(0) - now;
cyclic->cpu_time_us += cpu_time;
/* Check if cpu-time exceeds max allowed time */
--
2.25.1
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