sleep: fix deadlock in esp_timer_impl_advance after light sleep

When light sleep is started, the other CPU gets halted using DPORT
stall mechanism. This can happen while it is inside an esp_timer
critical section, which may lead to a deadlock. This change adds
functions to take and release esp_timer lock before entering
DPORT critical section, preventing the deadlock.
This commit is contained in:
Ivan Grokhotkov 2018-05-04 12:50:39 +08:00
parent 296b280801
commit 8c307a5720
4 changed files with 60 additions and 0 deletions

View File

@ -165,6 +165,16 @@ static inline void IRAM_ATTR timer_count_reload(void)
REG_WRITE(FRC_TIMER_LOAD_REG(1), REG_READ(FRC_TIMER_COUNT_REG(1)) - ALARM_OVERFLOW_VAL);
}
void esp_timer_impl_lock()
{
portENTER_CRITICAL(&s_time_update_lock);
}
void esp_timer_impl_unlock()
{
portEXIT_CRITICAL(&s_time_update_lock);
}
uint64_t IRAM_ATTR esp_timer_impl_get_time()
{
uint32_t timer_val;

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@ -84,3 +84,18 @@ uint64_t esp_timer_impl_get_time();
* @return minimal period of periodic timer, in microseconds
*/
uint64_t esp_timer_impl_get_min_period_us();
/**
* @brief obtain internal critical section used esp_timer implementation
* This can be used when a sequence of calls to esp_timer has to be made,
* and it is necessary that the state of the timer is consistent between
* the calls. Should be treated in the same way as a spinlock.
* Call esp_timer_impl_unlock to release the lock
*/
void esp_timer_impl_lock();
/**
* @brief counterpart of esp_timer_impl_lock
*/
void esp_timer_impl_unlock();

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@ -279,6 +279,11 @@ esp_err_t esp_light_sleep_start()
{
static portMUX_TYPE light_sleep_lock = portMUX_INITIALIZER_UNLOCKED;
portENTER_CRITICAL(&light_sleep_lock);
/* We will be calling esp_timer_impl_advance inside DPORT access critical
* section. Make sure the code on the other CPU is not holding esp_timer
* lock, otherwise there will be deadlock.
*/
esp_timer_impl_lock();
s_config.rtc_ticks_at_sleep_start = rtc_time_get();
uint64_t frc_time_at_start = esp_timer_get_time();
DPORT_STALL_OTHER_CPU_START();
@ -332,6 +337,7 @@ esp_err_t esp_light_sleep_start()
}
esp_set_time_from_rtc();
esp_timer_impl_unlock();
DPORT_STALL_OTHER_CPU_END();
rtc_wdt_disable();
portEXIT_CRITICAL(&light_sleep_lock);

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@ -91,6 +91,35 @@ TEST_CASE("light sleep stress test", "[deepsleep]")
vSemaphoreDelete(done);
}
TEST_CASE("light sleep stress test with periodic esp_timer", "[deepsleep]")
{
void timer_func(void* arg)
{
ets_delay_us(50);
}
SemaphoreHandle_t done = xSemaphoreCreateCounting(2, 0);
esp_sleep_enable_timer_wakeup(1000);
esp_timer_handle_t timer;
esp_timer_create_args_t config = {
.callback = &timer_func,
};
TEST_ESP_OK(esp_timer_create(&config, &timer));
esp_timer_start_periodic(timer, 500);
xTaskCreatePinnedToCore(&test_light_sleep, "ls1", 4096, done, UNITY_FREERTOS_PRIORITY + 1, NULL, 0);
#if portNUM_PROCESSORS == 2
xTaskCreatePinnedToCore(&test_light_sleep, "ls1", 4096, done, UNITY_FREERTOS_PRIORITY + 1, NULL, 1);
#endif
xSemaphoreTake(done, portMAX_DELAY);
#if portNUM_PROCESSORS == 2
xSemaphoreTake(done, portMAX_DELAY);
#endif
vSemaphoreDelete(done);
esp_timer_stop(timer);
esp_timer_delete(timer);
}
#ifdef CONFIG_ESP32_RTC_CLOCK_SOURCE_EXTERNAL_CRYSTAL
#define MAX_SLEEP_TIME_ERROR_US 200
#else