Failing controls transfers in VMware

[Markus Dolze]

Hans Petter Selasky wrote:
> On Tuesday 30 June 2009 22:11:47 Markus Dolze wrote:
>> Markus Dolze wrote:
>>> To repeat run the attached program:
>>>
>>>    1. Fill in some vendor / product ID of a device detected as ugen
>>> device 2. Compile and run the code (devel/libusb must be installed).
>>>
> 
> You should use this function when reading strings:
> 
> int     usb_get_string_simple(usb_dev_handle * dev, int index, char *buf, 
> size_t buflen);
> 

Yes, this is more easy, but I crafted the control transfers myself to
show that actually the control transfer is failing.

Libusb's usb_get_string_simple internally uses to control transfers to
read a string. The first one to get a list of supported languages and
the second one to actually retrieve the string. I found that the second
control transfer always errors out.

If I replace the usb_control_msg() in my test program with
usb_get_string_simple() I get:

root at freebsd7:./test
Found AVR-USB device
USB_control_msg result: -5
Warning: cannot query manufacturer for device: error sending control
message: Input/output error
USB_control_msg result: -5
Warning: cannot query product: error sending control message:
Input/output error

Thanks,
Markus