USB HOST 读取U盘

我使用正点原子的stm32F407阿波罗开发板。
现在重新编译工程，可以显示USB连接，
usb connected[2020-07-11 09:56:07.288]
msg type 0[2020-07-11 09:56:07.288]
port 1 status 0x10201[2020-07-11 09:56:07.292]
reset port[2020-07-11 09:56:07.544]
start enumnation[2020-07-11 09:56:07.594]，
然后就没有后面的
使用命令行ls

后面发现，程序卡在了drv_usbh.c
static int drv_pipe_xfer(upipe_t pipe, rt_uint8_t token, void *buffer, int nbytes, int timeouts)
{

int timeout = timeouts;

while (1)
{
    if (!connect_status)
    {
        return -1;
    }

    rt_completion_init(&urb_completion);
    HAL_HCD_HC_SubmitRequest(&stm32_hhcd_fs, pipe->pipe_index, (pipe->ep.bEndpointAddress & 0x80) >> 7,
            pipe->ep.bmAttributes, token, buffer, nbytes, 0);
    rt_completion_wait(&urb_completion, timeout);
    rt_thread_mdelay(10);
    if (HAL_HCD_HC_GetState(&stm32_hhcd_fs, pipe->pipe_index) == HC_NAK)
    {
        RT_DEBUG_LOG(RT_DEBUG_USB, ("nak\n"));
        if (pipe->ep.bmAttributes == USB_EP_ATTR_INT)
        {
            rt_thread_delay(
                    (pipe->ep.bInterval * RT_TICK_PER_SECOND / 1000) > 0 ?
                            (pipe->ep.bInterval * RT_TICK_PER_SECOND / 1000) : 1);
        }
        HAL_HCD_HC_Halt(&stm32_hhcd_fs, pipe->pipe_index);
        HAL_HCD_HC_Init(&stm32_hhcd_fs, pipe->pipe_index, pipe->ep.bEndpointAddress, pipe->inst->address,
        USB_OTG_SPEED_FULL, pipe->ep.bmAttributes, pipe->ep.wMaxPacketSize);
        continue;
    }
    else if (HAL_HCD_HC_GetState(&stm32_hhcd_fs, pipe->pipe_index) == HC_STALL)
    {
        RT_DEBUG_LOG(RT_DEBUG_USB, ("stall\n"));
        pipe->status = UPIPE_STATUS_STALL;
        if (pipe->callback != RT_NULL)
        {
            pipe->callback(pipe);
        }
        return -1;
    }
    else if (HAL_HCD_HC_GetState(&stm32_hhcd_fs, pipe->pipe_index) == URB_ERROR)
    {
        RT_DEBUG_LOG(RT_DEBUG_USB, ("error\n"));
        pipe->status = UPIPE_STATUS_ERROR;
        if (pipe->callback != RT_NULL)
        {
            pipe->callback(pipe);
        }
        return -1;
    }
    else if (URB_DONE == HAL_HCD_HC_GetURBState(&stm32_hhcd_fs, pipe->pipe_index))
    {
        RT_DEBUG_LOG(RT_DEBUG_USB, ("ok\n"));
        pipe->status = UPIPE_STATUS_OK;
        if (pipe->callback != RT_NULL)
        {
            pipe->callback(pipe);
        }
        size_t size = HAL_HCD_HC_GetXferCount(&stm32_hhcd_fs, pipe->pipe_index);
        if (pipe->ep.bEndpointAddress & 0x80)
        {
            return size;
        }
        else if (pipe->ep.bEndpointAddress & 0x00)
        {
            return size;
        }
        return nbytes;
    }

    continue;
}

}
函数里面了。我看一些人说是设备描述符超过64字节，这样就出问题了。