Re: [RFC] mac80211: fix resuming when device is gone

[Stanislaw Gruszka <sgruszka@redhat.com>]

On Tue, Aug 09, 2011 at 11:29:26AM +0200, Johannes Berg wrote:
> On Tue, 2011-08-09 at 11:28 +0200, Johannes Berg wrote:
> 
> > > I think I was unclear. The sta_cleanup timer callback, namely
> > > sta_info_cleanup(), can operate on freed memory. On
> > > ieee80211_unregister_hw() -> sta_info_stop() we delete this timer, but
> > > rdev/wiphy/local/hw structure is not freed. It's keep by reference
> > > counter. 
> > 
> > You mean by device_del(&rdev->wiphy.dev) right?
> > 
> > > Then if ieee80211_reconfig() is called, we schedule
> > > sta_cleanup timer. After that, when sysfs drop reference counter we
> > > free rdev. Then sta_info_cleanup() crash kernel.
> > 
> > Ok let me get this straight -- even after device_del() we get a resume
> > callback from the core subsystem? That doesn't seem right.
> 
> Or .. what else called ieee80211_reconfig()?

Only ieee80211_restart_work().

Note, I assumed that ieee80211_reconfig() have no sense
after ieee80211_unregister_hw()?

Stanislaw