I have written a DriverKit for a USB device and it seems to work well. It is a port from an existing KExt.
In the KExt I could call SuspendDevice(true) on IOUsbDevice and it would tell the hub to suspend the port to which the device is attached.
I could not find a way to do it in DriverKit. What am I missing? I looked at the headers in USBDriverKit and DriverKit (especially IOUSBHostDevice.iig).