Return-path: Received: from nbd.name ([46.4.11.11]:52137 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750956Ab1HMQF7 (ORCPT ); Sat, 13 Aug 2011 12:05:59 -0400 Message-ID: <4E46A0D9.3090906@openwrt.org> (sfid-20110813_180603_104713_78273B78) Date: Sat, 13 Aug 2011 10:05:45 -0600 From: Felix Fietkau MIME-Version: 1.0 To: Alexander Simon CC: Johannes Berg , linux-wireless@vger.kernel.org Subject: Re: [PATCH 4/4] mac80211: Add HT operation modes for IBSS References: <1888623.Vt5VZUN2cU@alex-1> <1312990268.3128.22.camel@alex-2> <1313152536.4022.9.camel@jlt3.sipsolutions.net> <2276990.7uHyxQX4MO@alex-1> In-Reply-To: <2276990.7uHyxQX4MO@alex-1> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2011-08-12 8:25 AM, Alexander Simon wrote: >> Ok, that makes sense. So you need the get_bss_ht() only for fixed mode I >> guess. > Exactly. >> >> > This should answer your last questions: >> > When not fixed, the BSSID configuration always is preferred. Thus, we >> > would join as HT40 even though not requested. >> > So, when we requsted HT40-, but the IBSS is HT40+, we would work on -. >> >> ? I think I know what you mean but your example seems .. the wrong way >> around? > Damn, you're right. We would work on HT+, not -, as the BSS config is > preferred. >> >> > I wanted to have the opportunity to start HT on an existing IBSS. >> >> Well that should always be OK? >> >> > The problem is that legacy station may "kill" the HT configuration: >> > If STA A starts in HT IBSS and lets say Windows STA B joins, B would >> > advertise that IBSS as non-HT as it ignores our HT IE. >> > Then, if STA A dies and STA C joins, it will be non-HT. >> >> mac80211 is STA C? Would it be a problem to use HT if the IBSS was >> previously non-HT? The old members will ignore it, but other new HT >> members may work OK? IOW -- is it not possible to have a mixed HT/non-HT >> IBSS? > Basically, as to my knowledge, the only difference is that we add HI IEs. Non- > HT stations will ignore these, of course. > A mixed network should be no problem - as long as Greenfield is turned off > (and i don't turn in on anywhere). > > To proceed with basics: I follow a very simple approach (for non-fixed freq): > Use current BSS HT settings. If none exists, use iw config. If no iw config, > no HT. What's the point of disabling HT in that case. Since it's a superset of normal A/B/G mode, we could just leave it enabled (defaulting to HT20) instead of reconfiguring based on beacons at a later point in time. - Felix