Need for ref/unref functions in watchdog drivers

[Guenter Roeck <linux@roeck-us.net>]

Hi,

I keep being puzzled about the ref/unref functions for watchdog drivers.

Hardly any driver implements those functions, even though many allocate
the watchdog_device data structure dynamically. At the same time, I don't
recall ever seeing a crash or traceback because of it.

Granted, many watchdogs are only loaded and never unloaded, but one
should think that the problem is seen at least once in a while.

Does anyone know how to trigger the problem which makes the ref/unref
functions necessary ? I would like to reproduce it and then try to find a better
solution, ie one that doesn't need those functions in the drivers (seems to me
the infrastructure should ensure that a driver isn't unloaded while in use).

Thanks,
Guenter