Re: [libusb] libusb_open returns -12 (LIBUSB_ERROR_NOT_SUPPORTED)

[Xiaofan C. <xia...@gm...>]

On Wed, Sep 22, 2021 at 7:37 AM Robert Ritchey
<R.R...@qu...> wrote:
>
> I am running under Windows and check for my device when I get a
> DBT_DEVICEARRIVAL event and check to see if it is gone when I get a
> DBT_DEVICEREMOVECOMPLETE event.
>
> The scenario is that I can open the device, do some transfers (actually
> download firmware), then tell the device to boot.  It disconnects, and I
> release the interface and close it successfully.
>
> When the firmware boots I get DBT_DEVICEARRIVAL event and look for
> my device. I can get the device list and descriptors but when I find my
> device and try to open I get this error.
>
> LIBUSB_ERROR_NOT_SUPPORTED seems like a strange error code to
> get for libusb_open.  I have single stepped through it many times and it
> seems right but I must be missing something.

I could be wrong but I believe there is no solution for now until hotplug
is supported by the Windows backend.
Ref: https://github.com/libusb/libusb/issues/86

Right now no developers are actively working on this feature so it will
take some time. In fact, since Chris seems to be busy after his last commit in
February 2021, there is no libusb developer on the Windows side as of now.



-- 
Xiaofan