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

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2011-08-09 at 13:36 +0200, Stanislaw Gruszka wrote:
> On Tue, Aug 09, 2011 at 11:45:13AM +0200, Johannes Berg wrote:
> > > > > 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.
> > > 
> > > No, ieee80211_reconfig() is called before device_del() (but can be
> > > called right after ieee80211_unregister_hw() and perhaps
> > > ieee80211_free_hw).
> > 
> > Ah so it's racy.
> > 
> > But I think you meant to say resume() is called before device_del()?
> 
> Yes, but __ieee80211_resume() calls directly ieee80211_reconfig().

Sure. Just trying to make sure I understand where it's coming from. So
wiphy_unregister() is still running, before device_del(), but then we
get the resume from the core...

Shouldn't we implement this logic you just did in cfg80211 instead?

johannes