RTThread USB转串口无法接收数据

发布于 2025-01-09 10:39:55 浏览：32 订阅该版

RTThread5.10版本串口V2，USB转串口在开启RT_DEVICE_FLAG_RX_NON_BLOCKING之后一直接收不到数据，后来发现串口的环形缓冲区和USB接收缓冲区不一致，导致数据无法向上传递，我只做了简单修改，修改如下：
```c
/**
 * This function will handle cdc bulk out endpoint request.
 *
 * @param func the usb function object.
 * @param size request size.
 *
 * @return RT_EOK.
 */
static rt_err_t _ep_out_handler(ufunction_t func, rt_size_t size)
{
    rt_base_t level;
    struct vcom *data;

RT_ASSERT(func != RT_NULL);

LOG_D("_ep_out_handler %d", size);

data = (struct vcom*)func->user_data;
    /* ensure serial is active */
    if((data->serial.parent.flag & RT_DEVICE_FLAG_ACTIVATED)
        && (data->serial.parent.open_flag & RT_DEVICE_OFLAG_OPEN))
    {
		//增加部分
        struct rt_serial_rx_fifo *rx_fifo;
        rx_fifo = (struct rt_serial_rx_fifo *) data->serial.serial_rx;
        RT_ASSERT(rx_fifo != RT_NULL);
		//
        /* receive data from USB VCOM */
        level = rt_hw_interrupt_disable();
		//增加部分
        rt_ringbuffer_put(&(rx_fifo->rb), data->ep_out->buffer, size);
		//
        rt_ringbuffer_put(&data->rx_ringbuffer, data->ep_out->buffer, size);
        rt_hw_interrupt_enable(level);

/* notify receive data */
        rt_hw_serial_isr(&data->serial,RT_SERIAL_EVENT_RX_IND);
    }

data->ep_out->request.buffer = data->ep_out->buffer;
    data->ep_out->request.size = EP_MAXPACKET(data->ep_out);
    data->ep_out->request.req_type = UIO_REQUEST_READ_BEST;
    rt_usbd_io_request(func->device, data->ep_out, &data->ep_out->request);

return RT_EOK;
}
```
在_ep_out_handler函数中增加上述部分，即可实现向上传递，解决问题