Subject: Re: [PATCH v2] mac80211: Add HT IE to IBSS beacons and probe
 responses.
From: Johannes Berg <johannes@sipsolutions.net>
To: Benoit Papillault <benoit.papillault@free.fr>
Cc: linux-wireless@vger.kernel.org
In-Reply-To: <4BE49BDD.8010803@free.fr>
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Date: Tue, 11 May 2010 12:48:12 +0200
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On Sat, 2010-05-08 at 01:01 +0200, Benoit Papillault wrote:

> > It would be helpful if you were to rebase over my patch that adds the
> > channel type tracking.
> 
> Your patches are now in wireless-testing, so I am doing it at the moment.

Thanks.

> >> +	if (channel_type != NL80211_CHAN_NO_HT&&
> >> +	    sband->ht_cap.ht_supported) {
> >
> > You shouldn't be able to get here with an HT channel but !ht_supported,
> > no? Or is that to support the case where you have HT only on one band?
> 
> Good point. I think there are several cases here :
> 
> - a non-HT STA is joining an HT IBSS (we need to check 802.11n-2009 to 
> see how it's supposed to be handled). In this case channel_type could be 
> ht40+ and ht_supported = false

Hmm, true.

> - an HT STA is joining a non-HT IBSS. It's clear in this case that no HT 
> IE should be sent, which is catched by (channel_type != 
> NL80211_CHAN_NO_HT) condition.

Right.

> Could we examine those cases in a follow up patch?

Well what do we actually need to do then?

> >> +}
> >> +
> >> +int ieee80211_add_ht_info(u8 **ppos,
> >> +			  struct ieee80211_supported_band *sband,
> >> +			  struct ieee80211_channel *channel,
> >> +			  enum nl80211_channel_type channel_type)
> >
> > what's wrong with ieee80211_add_ht_ie()
> 
> Seems it's close to what I'm doing, but not entirely the same. I will 
> read it. If applicable, should I move ieee80211_add_ht_ie to util.c (and 
> declaration to ieee80211_i.h) then ?

Yes.

Also I just noticed that there's a TODO item in rx.c when we receive an
HT frame from a peer we don't know about yet. Not sure what to do there,
but you'll need to look at it.

johannes