From: Bjorn Helgaas
Date: Thu, 24 Mar 2016 11:13:34 -0500
> netpoll_setup() does a dev_hold() on np->dev, the netpoll device. If it
> fails, it correctly does a dev_put() but leaves np->dev set. If we call
> netpoll_cleanup() after the failure, np->dev is still set so we do another
> dev_put(),
netpoll_setup() does a dev_hold() on np->dev, the netpoll device. If it
fails, it correctly does a dev_put() but leaves np->dev set. If we call
netpoll_cleanup() after the failure, np->dev is still set so we do another
dev_put(), which decrements the refcount an extra time.
It's questionable to