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esp_timer: Fix System time jumps back ~54secs

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Closes: https://github.com/espressif/esp-idf/issues/2513
This commit is contained in:
KonstantinKondrashov
2019-09-06 20:17:25 +08:00
parent 09cc922b42
commit f1e8a49836
2 changed files with 31 additions and 41 deletions
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56
components/esp32/esp_timer_esp32.c
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@@ -12,6 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
#include "sys/param.h"
#include "esp_err.h"
#include "esp_timer.h"
#include "esp_system.h"
@@ -127,13 +128,6 @@ static uint32_t s_timer_us_per_overflow;
// will not increment s_time_base_us if this flag is set.
static bool s_mask_overflow;
//The timer_overflow_happened read alarm register to tell if overflow happened.
//However, there is a monent that overflow happens, and before ISR function called
//alarm register is set to another value, then you call timer_overflow_happened,
//it will return false.
//So we store the overflow value when new alarm is to be set.
static bool s_overflow_happened;
#ifdef CONFIG_PM_DFS_USE_RTC_TIMER_REF
// If DFS is enabled, upon the first frequency change this value is set to the
// difference between esp_timer value and RTC timer value. On every subsequent
@@ -152,10 +146,6 @@ portMUX_TYPE s_time_update_lock = portMUX_INITIALIZER_UNLOCKED;
// Check if timer overflow has happened (but was not handled by ISR yet)
static inline bool IRAM_ATTR timer_overflow_happened()
{
if (s_overflow_happened) {
return true;
}
return ((REG_READ(FRC_TIMER_CTRL_REG(1)) & FRC_TIMER_INT_STATUS) != 0 &&
((REG_READ(FRC_TIMER_ALARM_REG(1)) == ALARM_OVERFLOW_VAL && TIMER_IS_AFTER_OVERFLOW(REG_READ(FRC_TIMER_COUNT_REG(1))) && !s_mask_overflow) ||
(!TIMER_IS_AFTER_OVERFLOW(REG_READ(FRC_TIMER_ALARM_REG(1))) && TIMER_IS_AFTER_OVERFLOW(REG_READ(FRC_TIMER_COUNT_REG(1))))));
@@ -222,35 +212,31 @@ uint64_t IRAM_ATTR esp_timer_impl_get_time()
void IRAM_ATTR esp_timer_impl_set_alarm(uint64_t timestamp)
{
portENTER_CRITICAL(&s_time_update_lock);
// Alarm time relative to the moment when counter was 0
uint64_t time_after_timebase_us = timestamp - s_time_base_us;
// Adjust current time if overflow has happened
bool overflow = timer_overflow_happened();
uint64_t cur_count = REG_READ(FRC_TIMER_COUNT_REG(1));
if (overflow) {
assert(time_after_timebase_us > s_timer_us_per_overflow);
time_after_timebase_us -= s_timer_us_per_overflow;
s_overflow_happened = true;
}
// Calculate desired timer compare value (may exceed 2^32-1)
uint64_t compare_val = time_after_timebase_us * s_timer_ticks_per_us;
uint32_t alarm_reg_val = ALARM_OVERFLOW_VAL;
// Use calculated alarm value if it is less than ALARM_OVERFLOW_VAL.
// Note that if by the time we update ALARM_REG, COUNT_REG value is higher,
// interrupt will not happen for another ALARM_OVERFLOW_VAL timer ticks,
// so need to check if alarm value is too close in the future (e.g. <2 us away).
const uint32_t offset = s_timer_ticks_per_us * 2;
if (compare_val < ALARM_OVERFLOW_VAL) {
if (compare_val < cur_count + offset) {
compare_val = cur_count + offset;
if (compare_val > ALARM_OVERFLOW_VAL) {
compare_val = ALARM_OVERFLOW_VAL;
}
do {
// Adjust current time if overflow has happened
if (timer_overflow_happened()) {
timer_count_reload();
s_time_base_us += s_timer_us_per_overflow;
}
alarm_reg_val = (uint32_t) compare_val;
}
REG_WRITE(FRC_TIMER_ALARM_REG(1), alarm_reg_val);
s_mask_overflow = false;
uint64_t cur_count = REG_READ(FRC_TIMER_COUNT_REG(1));
// Alarm time relative to the moment when counter was 0
int64_t time_after_timebase_us = (int64_t)timestamp - s_time_base_us;
// Calculate desired timer compare value (may exceed 2^32-1)
int64_t compare_val = time_after_timebase_us * s_timer_ticks_per_us;
compare_val = MAX(compare_val, cur_count + offset);
uint32_t alarm_reg_val = ALARM_OVERFLOW_VAL;
if (compare_val < ALARM_OVERFLOW_VAL) {
alarm_reg_val = (uint32_t) compare_val;
}
REG_WRITE(FRC_TIMER_ALARM_REG(1), alarm_reg_val);
} while (REG_READ(FRC_TIMER_ALARM_REG(1)) <= REG_READ(FRC_TIMER_COUNT_REG(1)));
portEXIT_CRITICAL(&s_time_update_lock);
}
@@ -261,7 +247,6 @@ static void IRAM_ATTR timer_alarm_isr(void *arg)
if (timer_overflow_happened()) {
timer_count_reload();
s_time_base_us += s_timer_us_per_overflow;
s_overflow_happened = false;
}
s_mask_overflow = false;
// Clear interrupt status
@@ -336,7 +321,6 @@ void esp_timer_impl_advance(int64_t time_us)
REG_WRITE(FRC_TIMER_ALARM_REG(1), 0);
REG_WRITE(FRC_TIMER_LOAD_REG(1), 0);
s_time_base_us += count / s_timer_ticks_per_us + time_us;
s_overflow_happened = false;
portEXIT_CRITICAL(&s_time_update_lock);
}