Re: [Libusb-devel] Still can't claim interface, "No such file or directory"

[Alan S. <st...@ro...>]

On Sun, 11 Oct 2009, Kustaa Nyholm wrote:

> Hi Alan,
> 
> thanks for responding.
> 
> Below is some output/code.

...
> 			USB_device device = findDevice(0x0FDE, 0xCA01, -1); //Ohio scientific
> 			assertOk(device != null ? 0 : NON_STD_ERR, "findDevice");
> 
> 			USB_dev_handle dev = usb_open(device);
> 			assertOk(dev != null ? 0 : NON_STD_ERR, "usb_open");
> 
> 			//ret = usb_detach_kernel_driver_np(dev, 0);
> 			//assertOk(ret, "usb_detach_kernel_driver_np");
> 
> 			ret = usb_set_configuration(dev, 0);
> 			assertOk(ret, "usb_set_configuration");
> 
> 			//ret = usb_claim_interface(dev, 0);
> 			assertOk(ret, "usb_claim_interface");
...

The problem is easy to fix.  You should not call 
usb_set_configuration() -- especially with a configuration value of 0.

If you do insist on calling it, then the configuration value (the
second argument) must be 1 and you should call it _before_ calling
usb_detach_kernel_driver_np(), not after.

Alan Stern