ESP32C3 power_save例程下串口收发数据，发现UART数据接收不正常，收不到正确数据，怎么解决？

g ESP32 C3, IDF 4.3.1版本， exampleswifipower_save这个例程，加上一个UART接收功能，发现UART数据接收不正常，收不到正确数据（但发UART数据可以）

测试程序如下：

// check if power save/light sleep will affect uart or not
static void uart_task(void *arg)
{
    /* Configure parameters of an UART driver,
     * communication pins and install the driver */
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
        .source_clk = UART_SCLK_APB,
    };
    int intr_alloc_flags = 0;

#if CONFIG_UART_ISR_IN_IRAM
    intr_alloc_flags = ESP_INTR_FLAG_IRAM;
#endif

    ESP_ERROR_CHECK(uart_driver_install(ECHO_UART_PORT_NUM, BUF_SIZE * 4, 0, 0, NULL, intr_alloc_flags));
    ESP_ERROR_CHECK(uart_param_config(ECHO_UART_PORT_NUM, &uart_config));
    ESP_ERROR_CHECK(uart_set_pin(ECHO_UART_PORT_NUM, ECHO_TEST_TXD, ECHO_TEST_RXD, ECHO_TEST_RTS, ECHO_TEST_CTS));

    // Configure a temporary buffer for the incoming data
    uint8_t *data = (uint8_t *) malloc(BUF_SIZE);

    while (1) {
        // Read data from the UART
        int len = uart_read_bytes(ECHO_UART_PORT_NUM, data, BUF_SIZE, 20 / portTICK_RATE_MS);

        if(len > 0) //         // Write data back to the UART
            uart_write_bytes(ECHO_UART_PORT_NUM, (const char *) data, BUF_SIZE);
                        
         vTaskDelay(20 / portTICK_PERIOD_MS);  // every uart command gap 8ms
        data[0] = 0;
    }
        
    free(data);
}

void app_main(void)
{
    // Initialize NVS
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK( ret );
        
#if CONFIG_PM_ENABLE
    // Configure dynamic frequency scaling:
    // maximum and minimum frequencies are set in sdkconfig,
    // automatic light sleep is enabled if tickless idle support is enabled.
    esp_pm_config_esp32c3_t pm_config = {
            .max_freq_mhz = CONFIG_EXAMPLE_MAX_CPU_FREQ_MHZ,
            .min_freq_mhz = CONFIG_EXAMPLE_MIN_CPU_FREQ_MHZ,
#if CONFIG_FREERTOS_USE_TICKLESS_IDLE  // note ,if enabled this (pw saving), uart will fail to work correctly
            .light_sleep_enable = true
#endif
    };
    ESP_ERROR_CHECK( esp_pm_configure(&pm_config) );
#endif // CONFIG_PM_ENABLE

    initialise_wifi();
        
    xTaskCreate(uart_task, "uart_rev_task", ECHO_TASK_STACK_SIZE, NULL, 10, NULL);  // configMAX_PRIORITIES - 0

    wifi_power_save();
}

当在menuconfig中disable power saving后，串口才能接收正常。
请问，是否是在light sleep 模式下， C3的串口接收不能正常工作？