I have written a resource manager which is running with priority higher than the devb-umass driver. The resource manager
 attaches to usb device via usbd_attach() and if the device is not the required one, it detaches it using usbd_detach().
 I have insertion and removal callbacks associated with the resource manager.

Since the devb-umass driver is also running, the usb device after being detached from the resource manager should be 
identified by devb-umass. But it is not happening. I am talking about the Mass Storage USB devices here.

1. Is there any other method which may notify devb-umass that the usb device is not being used by any other process now?

2. Apart from usbd_detach() is there any other API that should be called to free the usb device from resource manager? 
(I tried usbd_disconnect() but it hangs the resource manager).

Any help would be appreciated.

Thanks