I've found what I believe is a serious flaw in newbus.
When a driver that has a DEVICE_IDENTIFY method is loaded, the
identify method is called. If it finds supported hardware, it uses
BUS_ADD_CHILD to notify the parent bus of the presence of that
hardware. At some later point, during a bus rescan, the attach
routine is called for each device that was identified in this manner.
When the driver is unloaded, the device is detached, but it remains on
the bus's list of child devices. The next time the module is loaded,
its DEVICE_IDENTIFY method is called again, and incorrectly adds a
second child device to the bus, because it does not know that one
There is no way for DEVICE_IDENTIFY to check if a matching child
already exists on the bus, or for the module's event handler to unlist
the child when unloading.
The first time you load the module, you get foo0; the second time, you
get foo0 *and* foo1 referencing the same physical device; the third
time, you get foo0, foo1, and foo2, etc.
I've also seen something similar happen when multiple ndis drivers are
loaded; the first one re-attaches to the hardware when the second one