Subject: Re: [PATCH 1/2] wl12xx: Enable the IEEE80211_HW_SPECTRUM_MGMT hw
 flag
From: Johannes Berg <johannes@sipsolutions.net>
To: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Cc: coelho@ti.com, linux-wireless@vger.kernel.org
In-Reply-To: <1296033436.18570.391.camel@wimaxnb.nmp.nokia.com>
References: <1296030565-23778-1-git-send-email-juuso.oikarinen@nokia.com>
	 <1296030565-23778-2-git-send-email-juuso.oikarinen@nokia.com>
	 <1296030672.3635.13.camel@jlt3.sipsolutions.net>
	 <1296032537.18570.384.camel@wimaxnb.nmp.nokia.com>
	 <1296032659.3635.29.camel@jlt3.sipsolutions.net>
	 <1296033436.18570.391.camel@wimaxnb.nmp.nokia.com>
Content-Type: text/plain; charset="UTF-8"
Date: Wed, 26 Jan 2011 10:22:36 +0100
Message-ID: <1296033756.3635.30.camel@jlt3.sipsolutions.net>
Mime-Version: 1.0
Sender: linux-wireless-owner@vger.kernel.org

On Wed, 2011-01-26 at 11:17 +0200, Juuso Oikarinen wrote:
> On Wed, 2011-01-26 at 10:04 +0100, ext Johannes Berg wrote:
> > On Wed, 2011-01-26 at 11:02 +0200, Juuso Oikarinen wrote:
> > 
> > > Well I guess I'm stating the obvious here. The effects of the flag are:
> > > 
> > > - It causes mac80211 to add the spectrum mgmt capability bit, list of
> > > supported channels and TX power capability info into the assoc-req
> > > - It causes mac80211 to process channel switch actions
> > > - It causes mac80211 to process and react to TPC power constraint
> > > elements sent out in beacons
> > > - It causes mac80211 to respond to TPC report requests by the AP, albeit
> > > currently only by refusing them.
> > 
> > Right. But all of this is generic, no? Except maybe TPC?
> > 
> > > In addition to this, I plan to implement the TPC basic reporting,
> > > including mac80211 stuff if required (I still need to learn some more on
> > > the subject, specifically regarding the wl12xx chipset) and also I plan
> > > to implement quieting, though it's likely that wont need mac80211
> > > intervention with wl12xx at least.
> > > 
> > > AFAIK all these items are mandatory on the 5GHz band, at least in
> > > Europe.
> > > 
> > > So I don't see how this flag could be removed. Unless you wan't to make
> > > the above default behavior - but then adding for instance the spectrum
> > > mgmt bit into the capabilities assumes all chipset will be able handle
> > > all of the features?
> > 
> > Yeah, I was thinking those should be default, and the actual TPC
> > reporting would of course depend on hardware features? But then again
> > maybe TPC itself isn't necessarily implemented by drivers since not all
> > drivers implement setting the power correctly.
> 
> This *is* mandatory stuff, so in that perspective I guess it would make
> sense to remove the flag and make all of this default behavior. Indeed
> the mac80211 could be made to refuse the TCP basic reports unless the
> driver provides a call-back for that or sth like that.
> 
> Also, I guess it would be a valid assumption all drivers supporting the
> 5GHz band would also support setting the TX power - otherwise they will
> possibly violate regulations anyway - whether they say they state or not
> they have the specturm mgmt capability makes little difference.
> 
> As I mentioned, I plan to implement basic reporting once I find out how
> to do that - so I will be reviewing this functionality some more later.
> Maybe, if you like, I can consider removing the flag at that point?

Sure, makes sense, thanks for looking.

johannes