Windows下libusb与STM32 CDC设备通信报LIBUSB_ERROR_NOT_FOUND问题

背景 #

我用STM32F446RE制作了一款基础通信类USB设备，设备每秒发送一段文本。基于libusb编写的跨平台读取程序在Linux下运行正常，流程为：

• 列出所有设备
• 通过VID和PID筛选目标设备
• 打开设备
• 分离内核驱动
• 占用接口
• 提交批量传输接收数据并打印到终端

Windows下的问题 #

迁移到Windows后，首先遇到打开设备时的LIBUSB_ERROR_NOT_SUPPORTED错误。经查Windows默认不为USB CDC设备提供驱动，使用Zadig工具安装WinUSB通用驱动并移除分离内核驱动的代码后，设备可正常打开，但提交批量传输时出现LIBUSB_ERROR_NOT_FOUND错误。

调试日志（调试级别4） #

[ 0.077542] [00005830] libusb: debug [libusb_open] open 3.2
[ 0.078566] [000022f0] libusb: debug [libusb_claim_interface] interface 0
[ 0.078694] [000022f0] libusb: debug [winusbx_claim_interface] claimed interface 0
[ 0.079206] [000022f0] libusb: debug [windows_assign_endpoints] (re)assigned endpoint 82 to interface 0
[ 0.079853] [00000280] libusb: debug [windows_iocp_thread] ignoring overlapped 000000FB54DFF8D0 for handle 000002181F1A3310

[ 0.080480] [00000280] libusb: debug [windows_iocp_thread] ignoring overlapped 000000FB54DFF8D0 for handle 000002181F1A3310
[ 0.081122] [000022f0] libusb: debug [libusb_submit_transfer] transfer 000002181F1930E0
[ 0.081842] [00000280] libusb: debug [windows_iocp_thread] ignoring overlapped 000000FB54DFF8D0 for handle 000002181F1A3310
[ 0.085782] [000022f0] libusb: debug [add_to_flying_list] arm timer for timeout in 2000ms (first in line)
[ 0.086302] [00000280] libusb: debug [windows_iocp_thread] ignoring overlapped 000000FB54DFF8D0 for handle 000002181F1A3310
[ 0.086975] [000022f0] libusb: error [winusbx_submit_bulk_transfer] unable to match endpoint to an open interface - cancelling transfer
[ 0.087657] [00000280] libusb: debug [windows_iocp_thread] ignoring overlapped 000000FB54DFF9B0 for handle 000002181F1A3310
[ 0.088588] [000022f0] libusb: debug [arm_timer_for_next_timeout] no timeouts, disarming timer
Failed to submit bulk transfer: LIBUSB_ERROR_NOT_FOUND
[ 0.091200] [000022f0] libusb: debug [libusb_free_transfer] transfer 000002181F1930E0
[ 0.091677] [000022f0] libusb: debug [libusb_release_interface] interface 0

我完全无法理解这个问题，比如日志中显示(re)assigned endpoint 82，但我的代码中设置的端点为0x81，这才是设备发送数据的端点。我可以提供USBView的设备详情或更多代码片段。

代码片段 #

void LIBUSB_CALL bulk_callback(struct libusb_transfer* transfer) {
    if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
        std::cout << "Bulk transfer completed successfully. Received " << transfer->actual_length << " bytes" << std::endl;

        // 重新提交传输以持续接收数据
        int error = libusb_submit_transfer(transfer);
        if (error < 0) {
            std::cerr << "Error re-submitting transfer: " << libusb_error_name(error) << std::endl;
        }
    } else {
        std::cerr << "Transfer failed with status: " << libusb_error_name(transfer->status) << std::endl;
        libusb_free_transfer(transfer);
    }
}


int main() {
    int error = libusb_open(device, &m_selected_device);
    if (error < 0) {
        m_working = false;
        std::cerr << "Error: failed to open device: " << libusb_error_name(error) << std::endl;
        return;
    }

    error = libusb_claim_interface(m_selected_device, INTERFACE_NUMBER); // 0
    if (error < 0) {
        std::cerr << "Error claiming interface: " << libusb_error_name(error) << std::endl;
        return;
    }

    // 通信部分
    struct libusb_transfer* transfer = libusb_alloc_transfer(0);
    if (!transfer) {
        m_error = true;
        std::cerr << "Failed to allocate transfer" << std::endl;
        libusb_release_interface(m_selected_device, INTERFACE_NUMBER);
        clean_up();
        return;
    }

    // 分配接收数据的缓冲区
    unsigned char* buffer = (unsigned char*) malloc(TRANSFER_SIZE);
    if (!buffer) {
        std::cerr << "Failed to allocate buffer" << std::endl;
        libusb_free_transfer(transfer);
        libusb_release_interface(m_selected_device, INTERFACE_NUMBER);
        clean_up();
        return;
    }

    // 填充批量传输参数：端点、缓冲区、大小、回调函数
    libusb_fill_bulk_transfer(
            transfer,
            m_selected_device,
            ENDPOINT_IN, // 0x81
            buffer,
            TRANSFER_SIZE, // 64
            bulk_callback,
            NULL,
            TIMEOUT
    );

    // 向USB栈提交传输请求
    error = libusb_submit_transfer(transfer);
    if (error < 0) {
        std::cerr << "Failed to submit bulk transfer: " << libusb_error_name(error) << std::endl;
        free(buffer);
        libusb_free_transfer(transfer);
        libusb_release_interface(m_selected_device, INTERFACE_NUMBER);
        clean_up();
        return;
    }

    // 主循环
    while (m_working) {
        error = libusb_handle_events(m_context);
        if (error < 0) {
            std::cerr << "Error handling events: " << libusb_error_name(error) << std::endl;
            break;
        }
    }

    error = libusb_release_interface(m_selected_device, INTERFACE_NUMBER);
    if (error < 0) {
        std::cerr << "Error releasing interface: " << libusb_error_name(error) << std::endl;
    }

    free(buffer);
    if (m_selected_device) {
        libusb_close(m_selected_device);
        m_selected_device = NULL;
    }
    return 0;
}

内容的提问来源于stack exchange，提问作者Coffee Spoon