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

[Kustaa N. <Kus...@pl...>]

Thanks Allen for suggestion, unfortunately this did not fix the problem.

I tried commenting out the set configuration and also tried it
with value 1 and I tried moving the detach kernel drive call
earlier. Done this before and tried again. 

Just the same, no such directory.

The first time I run with the detach I get no such
directory at claim interface, the second time run
I get no route to host at the detach which condition
disappears if I re plug the device.

Im stumped.

Incidentally the exact same code works on Mac OS,
(apart from the detach) haven't tried Windows yet.

I don't get this to work soon I need to skip Linux
which would be a real pity as it would be the ideal
OS for this sort of standalone low performance
server application I'm doing.


br Kusti




________________________________________
From: Alan Stern [st...@ro...]
Sent: Monday, October 12, 2009 4:49 AM
To: Kustaa Nyholm
Cc: lib...@li...
Subject: Re: [Libusb-devel] Still can't claim interface, "No such file or directory"

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