Message-ID: <1400836074.4358.12.camel@jlt4.sipsolutions.net> (sfid-20140523_110847_374022_5F8EB18E)
Subject: Re: [PATCH v6 4/6] mac80211: use chanctx reservation for AP CSA
From: Johannes Berg <johannes@sipsolutions.net>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
	Luca Coelho <luca@coelho.fi>
Date: Fri, 23 May 2014 11:07:54 +0200
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On Fri, 2014-05-23 at 10:58 +0200, Michal Kazior wrote:

> If you keep on beaconing for too long on a DFS channel after detecting
> a radar you risk breaking local law (ETSI and FCC specify quiescing
> periods).

Yes, this is true.

> > You could technically just return NULL in this period, but I don't know
> > how well drivers would cope with that (though technically they have to
> > cope with it due to memory allocation failures anyway)
> 
> Sounds good to me.
> 
> I guess you'd use ieee80211_csa_is_complete (or
> ieee80211_csa_update_counter) for template-based drivers to stop
> beaconing.

The thing is, I don't see that template based drivers would be able to
stop beaconing :-)

This whole design that requires it seems a bit fishy to start with, so I
can't really imagine anyone writing firmware that supports it. That
said, ours only supports a single beacon at a time anyway, so we'll
switch immediately and don't have to do that anyway.

johannes