libusb基本例子想要的

我正在写用户空间程序，旨在通过USB控制某些设备，所以我决定使用libusb（libusb-1.0）发送控制消息，并从设备接收响应。

但是我经常从我的代码中收到以下一些错误（即使使用'sudo'执行）：

USB error: could not set config 0: Device or resource busy set configuration: failed Check that you have permissions to write to 007/012 and, if you don't, that you set up hotplug (http://linux-hotplug.sourceforge.net/) correctly. USB error: could not claim interface 0: Device or resource busy claim interface: failed USB error: error submitting URB: No such file or directory bulk writing: failed USB error: error submitting URB: No such file or directory bulk reading: failed response was: 

代码是：

 usb_dev_handle* find_device (); int main (int argc, char *argv[]) { usb_dev_handle* udev; int status; char request[] = "K1"; // 'ping' command used to check communication char response[256]; udev = find_device (); // udev is successfully found here status = usb_set_configuration (udev, 0); printf ("set configuration: %s\n", status ? "failed" : "passed"); status = usb_claim_interface (udev, 0); printf ("claim interface: %s\n", status ? "failed" : "passed"); status = usb_bulk_write (udev, 3, request, sizeof (request), 500); printf ("bulk writing: %s\n", status ? "failed" : "passed"); status = usb_bulk_read (udev, 2, response, sizeof (response), 500); printf ("bulk reading: %s\n", status ? "failed" : "passed"); printf ("response was: %s\n", response); usb_close (udev); return 0; } 

代码有什么问题？ 怎样才能解决？

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操作系统：Ubuntu 10.10

 libusb_init(NULL); libusb_open_device_with_vid_pid(NULL, vendor_id, product_id); libusb_detach_kernel_driver(devh, 0); libusb_claim_interface(devh, 0); libusb_close(devh); libusb_exit(NULL); 

 static struct libusb_device_handle *devh = NULL; uint16_t vendor_id; uint16_t product_id;