Message-ID: <1352129245.9466.21.camel@jlt4.sipsolutions.net> (sfid-20121105_162706_339906_4436CD34)
Subject: Re: [PATCH v4 5/6] nl80211/cfg80211: add ap channel switch command
From: Johannes Berg <johannes@sipsolutions.net>
To: Victor Goldenshtein <victorg@ti.com>
Cc: linux-wireless@vger.kernel.org, kgiori@qca.qualcomm.com,
	mcgrof@frijolero.org, zefir.kurtisi@neratec.com,
	adrian.chadd@gmail.com, j@w1.fi, coelho@ti.com, igalc@ti.com,
	adrian@freebsd.org, nbd@nbd.name,
	simon.wunderlich@s2003.tu-chemnitz.de
Date: Mon, 05 Nov 2012 16:27:25 +0100
In-Reply-To: <50922AA3.7000404@ti.com>
References: <1350226137-13704-1-git-send-email-victorg@ti.com>
	   <1350226137-13704-6-git-send-email-victorg@ti.com>
	  <1350414390.10177.16.camel@jlt4.sipsolutions.net>
	 <5084256F.2030502@ti.com> <1350910332.10166.0.camel@jlt4.sipsolutions.net>
	 <50922AA3.7000404@ti.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

On Thu, 2012-11-01 at 09:54 +0200, Victor Goldenshtein wrote:

> >> Yes it works with our 12xx, in the 12xx the FW (upon channel switch
> >> command) is responsible to decrement the channel switch count in the
> >> beacon CSA IE and to remove the CSA IE from the beacon once device moves
> >> to the new channel (+ to updates the DS).
> >
> > So ... you've made this kind of behaviour a mandatory part of the
> > userspace API. Where is it documented then? How will it work with other
> > devices?
> 
> It's should work the same with other devices, each device should 
> implement AP channel switch op according the spec, the implementation 
> can be hardware/driver depended. I just mentioned how we do it in our 
> devices, which I think is the right way without introducing any races 
> (as you mentioned), So no behavior enforcement here as long as it 
> according the spec.

I don't think that's how it works ... you should describe what is
expected of the driver in the right API documentation. Even saying
"implement the procedures as described in 802.11-2012 section ..." could
be sufficient, but I think that needs to be there.

johannes