All HostController, Endpoint and Device references have an associated reference count. This count is incremented by the associated find calls for them, and needs to be decremented when they are no-longer of use to the driver. A reference can be de-registered by USBLib_ReferenceDeregister (SWI &56372) which will take one off the reference count. When the reference count reaches zero, the reference will finally be deleted from the system, freeing up any associated resources.

If the reference counts are not suitably de-registered, then you will leave references and their resources in the system, and will therefore leave less room for new resources.

The reference count of of endpoints created when the device is first obtained by the driver may well not be zero, drivers should not assume this behaviour and should balance claims and releases accordingly.