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,
> 
> pleaded about my problems previously and get some suggestions but 
> nothing helps.
> 
> When I run my code to access my weather station that advertises itself
> as HID device I run into the following issue:
> 
> I do the normal libusb (0.1) stuff of usb_init()/usb_find_buses()/usb_find_devices()
> and all this works every time, I can find my device no problem.
> 
> I can also set the configuration with usb_set_configuration() but
> when I try to  usb_claim_interface() I get "device busy"
> and indeed dmesg I see that the interface has been claimed
> by usbhid.
> 
> So I unbind it with usb_detach_kernel_driver_np()  after
> which an attempt to  claim interface returns "no such file or directory".
> 
> But I can still enumerate the buses and devices and find my
> device! What is going on?

Can't tell from your verbal description.  What's in the dmesg log?

> So obviously usbhid is claiming my device in the first place
> and I can force it to detatch itself but then libusb cannot
> claim it? How can the libusb find the device in the
> enumration phase but not find it when I try to claim the 
> interface?

Perhaps if you post the source code, the problem might be apparent.

Alan Stern