On Sun, Jun 1, 2014 at 8:10 AM, Xiaofan Chen <[email protected]> wrote: > I think you hit one of WinUSB's limitation. > > - with WinUSB configured to point to my composite device > (ie DeviceID = "VID_0403&PID_7C38"), this fails after 32 iterations > (way down in the guts of libusb - basically after 32 iterations it runs > out of valid interfaces). > > - with WinUSB configured with two interfaces (ie DeviceID_0 = > "VID_0403&PID_7C38&MI_00" and DeviceID_1 = > "VID_0403&PID_7C38&MI_01"), this run without any issues. > > To use WinUSB as the driver for the USB composite device parent, > you have to claim the first interface first (interface 0, or channel A). > Ref: > http://msdn.microsoft.com/en-us/library/windows/hardware/ff540245(v=vs.85).aspx > > Again, libusbk.sys does not have such limitation, you should > try libusbk.sys instead (you will need libusbK.dll).
This may not be correct. libusb Windows backen will try to auto-claim the default interface. -- Xiaofan -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
