Re: [Libusbx-devel] Getting "unsupported API call for 'open'" on Windows 8.1 libusb

[Matthias B. <mat...@go...>]

2014-07-29 23:28 GMT+02:00 Bob Tausworthe <to...@se...>:
> Sorry to trouble you but I've exhausted other options. We are developing a
> composite HID/debug interace device and are using libusb 1.0 under 32 bit
> Cygwin to access the debug interface portion. Everything is working fine on
> Windows 7 and Linux but when we try to run the application on Windows 8, it
> fails with the error :
>
> libusb: debug [unsupported_open] unsupported API call for 'open'
> (unrecognized device driver)
> libusb: debug [libusb_open] open 2.16 returns -12
> ERROR: Unable to open usb device
>
> After reading some posts of people with similar issues, I tried all of the
> drivers Zadig supports but didn't see any difference in behavior. I have
> tried building under Win7 and Win8 but the results are the same. I am using
> version 1.0.18 of libusb. The trace below was taken with the WinUSB driver
> version 6.1.7600.16385.
>
> Any help you can give me to point me in the right direction would be
> welcome. Here is the code I'm using to open our device and the trace
> listing.
>
> Thanks
>
> Bob Tausworthe
> to...@se...
> Sentons, inc.
>
> int
>
> InitUSB(void)
>
> {
>
>    // Change these as needed to match idVendor and idProduct in your
> device's device descriptor.
>
>    int device_ready = 0;
>
>    int result;
>
>   libusb_device **list;
>
>   libusb_device *found = NULL;
>
>   libusb_context *ctx = NULL;
>
>   int attached = 0;
>
>   result = libusb_init(&ctx);
>
>   if (result == 0) {
>
>   if (usb_trace_enabled)
>
>   libusb_set_debug(ctx,255); // LIBUSB_LOG_LEVEL_DEBUG,
> LIBUSB_LOG_LEVEL_WARNING
>
>   ssize_t i = 0;
>
>   int err = 0;
>
>   ssize_t cnt = libusb_get_device_list(ctx, &list);
>
>   if (cnt < 0){
>
>     fprintf(stderr, "ERROR: no usb devices found\n" );
>
>     error();
>
>   }
>
>   // find our device. Note we are using the brute force method rather
>
>   // than open_device_with_vid_pid() because we need the device pointer
>
>   // to look at the config descriptor.
>
>   for(i = 0; i < cnt; i++){
>
>     libusb_device *device = list[i];
>
>     if( is_correctdev(device) ){

How does the is_correctdev() function decide which device to pick?

-- 
Matthias Bolte
http://photron.blogspot.com