[libhid-discuss] Re: How to use multiple interfaces?

[Charles Lepple]

BTW, please use the libhid-discuss list at alioth:

http://lists.alioth.debian.org/mailman/listinfo/libhid-discuss

The old list at ailab.ch is being shut down.

On Mar 8, 2007, at 7:28 PM, Velu, Muthu wrote:
> Charles,
> I have an HID device with multiple interfaces (0-3) with IN  
> endpoints (81-84) respectively.
>
> It works OK if  I use with interface 0.
>
> When I tried hid_force_open() with interface 1, I got the following  
> error.
> "WARNING: hid_prepare_hid_descriptor(): failed to get HID  
> descriptor for USB device 004/003[1] "
Can you increase the log level and copy the entire set of messages?

You may also need to set the USB_DEBUG environment variable to see  
why this call is failing.
> I noticed the comment on hid_prepare_hid_descriptor() function and  
> realized it always uses USB_ENDPOINT_IN+1.
>
> So I changed it to USB_ENDPOINT_IN+2 but still getting the same error.
>
> I am using libhid-0.2.15+20060325 version of the library.
>
> What should I do to get it work?
>
> Should I use another version of the libray?

I would advise using the SVN version if you can. See details on the  
libhid home page:

http://libhid.alioth.debian.org/

-- 
Charles Lepple