Return-path: Received: from mail.candelatech.com ([208.74.158.172]:48772 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964828Ab3CSUqn (ORCPT ); Tue, 19 Mar 2013 16:46:43 -0400 Message-ID: <5148CEAD.3010908@candelatech.com> (sfid-20130319_214649_009268_561037B9) Date: Tue, 19 Mar 2013 13:46:37 -0700 From: Ben Greear MIME-Version: 1.0 To: Johannes Berg CC: linux-wireless@vger.kernel.org Subject: Re: [PATCH v2] mac80211: Don't restart sta-timer if not associated. References: <1363307043-23771-1-git-send-email-greearb@candelatech.com> (sfid-20130315_012436_532333_DCDE8CD4) <1363724490.8336.18.camel@jlt4.sipsolutions.net> In-Reply-To: <1363724490.8336.18.camel@jlt4.sipsolutions.net> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 03/19/2013 01:21 PM, Johannes Berg wrote: > On Thu, 2013-03-14 at 17:24 -0700, greearb@candelatech.com wrote: >> From: Ben Greear >> >> I found another crash when deleting lots of virtual stations >> in a congested environment. I think the problem is that >> the ieee80211_mlme_notify_scan_completed could call >> ieee80211_restart_sta_timer for a non-associated interface >> that was about to be deleted. >> >> With the following patch I am unable to reproduce the >> crash. >> >> Signed-off-by: Ben Greear >> --- >> v2: Be more selective: Still need to do sdata->work even >> if not associated so that we *can* associate. >> >> :100644 100644 81e0619... da805e2... M net/mac80211/mlme.c >> net/mac80211/mlme.c | 7 +++++-- >> 1 files changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c >> index 81e0619..da805e2 100644 >> --- a/net/mac80211/mlme.c >> +++ b/net/mac80211/mlme.c >> @@ -2935,11 +2935,14 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata) >> >> /* let's probe the connection once */ >> flags = sdata->local->hw.flags; >> - if (!(flags & IEEE80211_HW_CONNECTION_MONITOR)) >> + if ((!(flags & IEEE80211_HW_CONNECTION_MONITOR)) && >> + sdata->u.mgd.associated) > > You really didn't need those extra parentheses :-) I like them :) ...never can remember if the ! operator takes precedence over &&, but can remove them... >> ieee80211_queue_work(&sdata->local->hw, >> &sdata->u.mgd.monitor_work); >> + >> /* and do all the other regular work too */ >> - ieee80211_queue_work(&sdata->local->hw, &sdata->work); >> + if (ieee80211_sdata_running(sdata)) >> + ieee80211_queue_work(&sdata->local->hw, &sdata->work); > > Overall, it seems that it would be safe to just check > ieee80211_sdata_running() in the beginning of the function instead? I'm not sure. I can look at the code closer tomorrow perhaps. > Maybe you could also look at the ibss/mesh code and fix this issue for > good? Will poke around in that as well, but I have no way to test it currently. Ben > > johannes > -- Ben Greear Candela Technologies Inc http://www.candelatech.com