Subject: Re: [PATCH] mac80211: use beacons for connection monitoring
From: Johannes Berg <johannes@sipsolutions.net>
To: Ben Greear <greearb@candelatech.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>,
	linville@tuxdriver.com, linux-wireless@vger.kernel.org
In-Reply-To: <4A70C17B.6090309@candelatech.com>
References: <1248903159-17024-1-git-send-email-reinette.chatre@intel.com>
	 <4A70C17B.6090309@candelatech.com>
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Date: Thu, 30 Jul 2009 12:30:53 +0200
Message-Id: <1248949853.29062.3.camel@johannes.local>
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Sender: linux-wireless-owner@vger.kernel.org


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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<reinette.chatre@intel.com>
> >
> > 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.
>=20
> 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.

johannes

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