Automatic light sleep works incorrectly if CONFIG_ESP32_TIME_SYSCALL_USE_RTC is set

[MikitaMinau]

Conditions
Chip: ESP32
IDF version: v4.3
Power Management settings:

Code: Select all

esp_pm_config_esp32_t pm_config =
    {
        .max_freq_mhz = ESP32_CORE_MAX_SPEED_MHZ,
        .min_freq_mhz = ESP32_CORE_MIN_SPEED_MHZ,
        .light_sleep_enable = true
    };
    ESP_ERROR_CHECK(esp_pm_configure(&pm_config));

BLE is on. WiFi is off.

When CONFIG_ESP32_TIME_SYSCALL_USE_RTC is set, I see the following issues
1. ESP is advertising over BLE but cannot connect to it.
2. RTOS generates longer delay with vTaskDelay than I request. When I request 1 second delay I get ~15.

If I set CONFIG_ESP32_TIME_SYSCALL_USE_RTC_FRC1 the problem disappears. I have not found any information in IDF spec about dependency between automatic light sleep and CONFIG_ESP32_TIME_SYSCALL.