Function esp_idf_svc::sys::uart_set_tx_empty_threshold

pub unsafe extern "C" fn uart_set_tx_empty_threshold(
    uart_num: u32,
    threshold: i32,
) -> i32

@brief Set uart threshold values for TX fifo empty

@param uart_num UART port number, the max port number is (UART_NUM_MAX -1) @param threshold Threshold value below which TX fifo empty interrupt is generated

@return - ESP_OK Success - ESP_ERR_INVALID_ARG Parameter error - ESP_ERR_INVALID_STATE Driver is not installed