kobj
func
data
owner
sysfs attribute methods must not unregister themselves or their parent kobject (which would amount to the same thing). Attempts to do so will deadlock, since unregistration is mutually exclusive with driver callbacks.
Instead methods can call this routine, which will attempt to allocate and schedule a workqueue request to call back func with data as its argument in the workqueue's process context. kobj will be pinned until func returns.
Returns 0 if the request was submitted, -ENOMEM if storage could not be allocated, -ENODEV if a reference to owner isn't available, -EAGAIN if a callback has already been scheduled for kobj.