stm32的usart中断发送却以轮询发送的方式

发布于 2024-07-23 10:36:05 浏览：245 订阅该版

[tocm]

# 串口中断发送却是用轮询发送方式
代码如下：
```c
rt_inline int _serial_int_tx(struct rt_serial_device *serial, const rt_uint8_t *data, int length)
{
    int size;
    struct rt_serial_tx_fifo *tx;

RT_ASSERT(serial != RT_NULL);

size = length;
    tx = (struct rt_serial_tx_fifo*) serial->serial_tx;
    RT_ASSERT(tx != RT_NULL);

while (length)
    {
        /*
         * to be polite with serial console add a line feed
         * to the carriage return character
         */
        if (*data == '\n' && (serial->parent.open_flag & RT_DEVICE_FLAG_STREAM))
        {
            if (serial->ops->putc(serial, '\r') == -1)
            {
                rt_completion_wait(&(tx->completion), RT_WAITING_FOREVER);
                continue;
            }
        }

if (serial->ops->putc(serial, *(char*)data) == -1)
        {
            rt_completion_wait(&(tx->completion), RT_WAITING_FOREVER);
            continue;
        }

data ++; length --;
    }

return size - length;
}
```
调用了
```c
static int stm32_putc(struct rt_serial_device *serial, char c)
{
    struct stm32_uart *uart;
    RT_ASSERT(serial != RT_NULL);

uart = rt_container_of(serial, struct stm32_uart, serial);
    UART_INSTANCE_CLEAR_FUNCTION(&(uart->handle), UART_FLAG_TC);
#if defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32WL) || defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32F0) \
    || defined(SOC_SERIES_STM32L0) || defined(SOC_SERIES_STM32G0) || defined(SOC_SERIES_STM32H7) || defined(SOC_SERIES_STM32L5) \
    || defined(SOC_SERIES_STM32G4) || defined(SOC_SERIES_STM32MP1) || defined(SOC_SERIES_STM32WB) || defined(SOC_SERIES_STM32F3)  \
    || defined(SOC_SERIES_STM32U5)
    uart->handle.Instance->TDR = c;
#else
    uart->handle.Instance->DR = c;
#endif
    while (__HAL_UART_GET_FLAG(&(uart->handle), UART_FLAG_TC) == RESET);

return 1;
}
```
_serial_int_tx函数不会运行到rt_completion_wait(&(tx->completion), RT_WAITING_FOREVER);这一句，中断中也不会发送完成信号。