Re: [PATCH 1/2] char_dev: pin parent kobject

This series looks good to me, and looks to fix the issue about as
cleanly as it can. Al, holler if you have any concerns, but I'm
planning on applying it ASAP,

            Linus

On Mon, Oct 22, 2012 at 3:57 AM, Dmitry Torokhov
[off-list ref] wrote:

In certain cases (for example when a cdev structure is embedded into
another object whose lifetime is controlled by a separate kobject) it is
beneficial to tie lifetime of another object to the lifetime of character
device so that related object is not freed until after char_dev object is
freed. To achieve this let's pin kobject's parent when doing cdev_add()
and unpin when last reference to cdev structure is being released.