Return-path: Received: from mail.candelatech.com ([208.74.158.172]:53955 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbZG3Olo (ORCPT ); Thu, 30 Jul 2009 10:41:44 -0400 Message-ID: <4A71B10E.20808@candelatech.com> Date: Thu, 30 Jul 2009 07:41:18 -0700 From: Ben Greear MIME-Version: 1.0 To: Johannes Berg CC: Reinette Chatre , linville@tuxdriver.com, linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: use beacons for connection monitoring References: <1248903159-17024-1-git-send-email-reinette.chatre@intel.com> <4A70C17B.6090309@candelatech.com> <1248949853.29062.3.camel@johannes.local> In-Reply-To: <1248949853.29062.3.camel@johannes.local> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: Johannes Berg wrote: > On Wed, 2009-07-29 at 14:39 -0700, Ben Greear wrote: > >> On 07/29/2009 02:32 PM, Reinette Chatre wrote: >> >>> From: Reinette Chatre >>> >>> The connection monitor currently relies on probe requests paired >>> with probe responses to ensure that a connection is alive. This is >>> fragile in some environments where probe responses can get lost. >>> When we receive beacons we can also consider the connection to be >>> alive, so cancel connection poll instance when we receive a beacon. >>> >> I'm chasing a similar problem while working on virtual STA device >> support in ath5k. I was also going to try sending up to 3 polls before >> giving up on the connection. Does that seems like a valid thing to do? >> > > That seems somewhat better, yeah. > > I suspect the real cause of the issue is something else though, like the > probe request not going out properly or the card being in a kind of > 'temporary lock-up' state where it's not really doing anything for the > time being -- I've never had a problem on any other (than iwlwifi) > hardware. > > Of course, the virtual STA device support stuff potentially has similar > issues, especially if it does channel switching like the ath9k virtual > wiphy stuff. > We're not trying any channel switching, though it does seem to stop transmitting and/or receiving for a bit during some operations. The retransmit logic was helping, but it still isn't quite right. Hopefully we'll make more progress today. Thanks, Ben > johannes > -- Ben Greear Candela Technologies Inc http://www.candelatech.com