Problem with libusb20_dev_get_port_path()

[Uffe Jakobsen]

On 2015-01-22 00:29, Uffe Jakobsen wrote:
>
>
> On 2015-01-20 22:44, Hans Petter Selasky wrote:
>> On 01/20/15 20:48, Uffe Jakobsen wrote:
>>>
>>> On 2015-01-20 12:45, Hans Petter Selasky wrote:
>>>>
>>>> It appears there is a minor bug in the kernel regarding this field. See
>>>> below:
>>>>
>>>> https://svnweb.freebsd.org/changeset/base/277417
>>>>
>>>> Should work now.
>>>>
>>>
>>> Thanks for the quick response and fix
>>>
>>> How far back does the problem reach ?
>>>
>>>
>>
>>
>> I think the IOCTL never worked except returning no path (0) like you
>> observed.
>>
>
> Ok, thanks
>
> Another observation around the cross-platform use of
> libusb20_dev_get_port_path() and libusb_get_port_numbers():
>
> On FreeBSD it seems that one needs to perform the respective usb open
> calls for the device before the two calls above succeeds without an
> negative error code.
>
> Whereas the usb open calls does not seem to be needed with the linux
> impl of libusb.
>
> Different behaviour between libusb on FreeBSD and linux creates a
> compatibility problems where linux-maintained programs accessing
> libusb20_dev_get_port_path() and libusb_get_port_numbers() will fail on
> FreeBSD but works on linux. (I've just spent some hours with such
> program) :-)
>
> I've looked through the available documentation without finding anything
> substantial - and hence I do not know which one is "right".
>

My previous post stated that libusb20_dev_get_port_path() is available 
on linux - it is not - libusb_get_port_numbers() is

Sorry about that

/Uffe