Re: [Libusb-devel] what does a LIBUSB_TRANSFER_STALL on control transfer mean?

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

On Fri, Apr 13, 2012 at 11:03 PM, bob 295 <ica...@29...> wrote:
> I'm still very much a USB/libusb-1.0 newbie.
>
> I've been trying to teach myself the libusb-1.0 library against a Phidgets SBC
> board.    This board comes with libusb-0.1 source code,  albeit a tad
> difficult to follow.   The relevant libusb-0.1 call I'm trying to emulate in
> async libusb-1.0 is:
>
> =========  begin Phidget lib snip =============
>  BytesWritten = usb_control_msg((usb_dev_handle *)phid->deviceHandle,
>                                        USB_ENDPOINT_OUT | USB_TYPE_CLASS |
> USB_RECIP_INTERFACE,
>                                        USB_REQ_SET_CONFIGURATION,
>                                        0x0200, /* value */
>                                        phid->deviceDef->pdd_iid, /* index*/
>                                        (char *)buffer,
>                                        phid->outputReportByteLength, /* size
> */
>                                        500); /* FIXME? timeout */
> =========== end Phidget lib snip ===========

In this case, I will suggest you not to jump from synchronous
transfer to async transfer in your first trying of libusb-1.0.

Try to translate the above sync control transfer to the
sync control transfer libusb-1.0 API first. Once that is
working, then you can try async API.


-- 
Xiaofan