Message-ID: <1369427323.8290.37.camel@jlt4.sipsolutions.net> (sfid-20130524_222904_312288_15E26AF0)
Subject: Re: Bisected 3.9 regression for iwl4965 connection problem to
 1672c0e3
From: Johannes Berg <johannes@sipsolutions.net>
To: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Jake Edge <jake@lwn.net>, linux-wireless@vger.kernel.org,
	lkml <linux-kernel@vger.kernel.org>
Date: Fri, 24 May 2013 22:28:43 +0200
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On Wed, 2013-05-22 at 13:59 +0200, Stanislaw Gruszka wrote:

> > AFICT, we wake queues only if beacon arrives or mac80211 call drv_config
> > with BSS_CHANGED_IDLE. I'm not sure if the latter prevent stuck. 
> 
> It should prevent stuck. When we fail to auth, drv_config() with BSS_CHANGED_IDLE
> is called via:
> 
> ieee80211_destroy_auth_data ->
> ieee80211_vif_release_channel ->
> __ieee80211_vif_release_channel ->
> ieee80211_unassign_vif_chanctx ->
> ieee80211_bss_info_change_notify
> 
> But there is need to have ->vif.chanctx_conf valid in 
> __ieee80211_vif_release_channel(), where is below condition:
> 
>         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
>                                          lockdep_is_held(&local->chanctx_mtx));
>         if (!conf)
>                 return;
> 
> I'm not sure if that always happen. Perhaps would be better to change
> BSS_CHANGED_IDLE to BSS_CHANGED_BSSID, which is called directly from
> ieee80211_destroy_auth_data() ?

I don't think the "!conf" can hit in this case, since to even try to
associate you have to have a channel context assigned.

johannes