10 使用DMA模式的串口，关闭设备后，再打开出现断言错误

发布于 2020-12-08 11:46:24 浏览：1151 订阅该版

在`stm32_dma_config(struct rt_serial_device *serial, rt_ubase_t flag)`函数里的    
```c
if (HAL_DMA_DeInit(DMA_Handle) != HAL_OK)
    {
        RT_ASSERT(0);
    }
```
跳进去看是DMA总线BUSY，我用的串口是DMA发送和接收；
```c
if(hdma->State == HAL_DMA_STATE_BUSY)
  {
    /* Return error status */
    return HAL_BUSY;
  }
  
```

以为关闭设备时没关闭串口和DMA，后面又加上了关闭串口和DMA以及中断,还是不好使，求助！！！！！！！！！！
```c
  static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *arg)
{
    struct stm32_uart *uart;
#ifdef RT_SERIAL_USING_DMA
    rt_ubase_t ctrl_arg = (rt_ubase_t)arg;
#endif

RT_ASSERT(serial != RT_NULL);
    uart = rt_container_of(serial, struct stm32_uart, serial);

switch (cmd)
    {
    /* disable interrupt */
    case RT_DEVICE_CTRL_CLR_INT:
		
	HAL_UART_DeInit(&uart->handle);  //关闭串口及DMA
	HAL_UART_DMAStop(&uart->handle);
        /* disable rx irq */
        NVIC_DisableIRQ(uart->config->irq_type);
        /* disable interrupt */
        __HAL_UART_DISABLE_IT(&(uart->handle), UART_IT_RXNE);
		__HAL_UART_DISABLE_IT(&(uart->handle), UART_IT_IDLE);
		__HAL_UART_DISABLE_IT(&(uart->handle), UART_IT_TC);
        break;
    /* enable interrupt */
    case RT_DEVICE_CTRL_SET_INT:
        /* enable rx irq */
        NVIC_EnableIRQ(uart->config->irq_type);
        /* enable interrupt */
        __HAL_UART_ENABLE_IT(&(uart->handle), UART_IT_RXNE);
        break;

#ifdef RT_SERIAL_USING_DMA
    case RT_DEVICE_CTRL_CONFIG:
        stm32_dma_config(serial, ctrl_arg);
        break;
#endif
    }
    return RT_EOK;
}
```