From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.redhat.com ([66.187.237.31]:58137 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759426AbZCPQ7F (ORCPT ); Mon, 16 Mar 2009 12:59:05 -0400 Subject: Re: [PATCH] cfg80211: drop wext channel list if too long From: Dan Williams To: Johannes Berg Cc: "John W. Linville" , linux-wireless In-Reply-To: <1237019432.5235.61.camel@johannes.local> References: <1236882244.25931.5.camel@johannes.local> <20090313145445.GC5551@tuxdriver.com> <1236964730.9657.10.camel@localhost.localdomain> <1237019432.5235.61.camel@johannes.local> Content-Type: text/plain Date: Mon, 16 Mar 2009 12:56:51 -0400 Message-Id: <1237222611.16956.17.camel@localhost.localdomain> (sfid-20090316_175919_378772_B1FE1200) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sat, 2009-03-14 at 09:30 +0100, Johannes Berg wrote: > On Fri, 2009-03-13 at 13:18 -0400, Dan Williams wrote: > > > It doesn't look like wpa_supplicant cares about the returned channel > > list from SIOCGIWRANGE. > > > > NM, however, uses the returned channel list to figure out a free > > supported adhoc frequency to use when creating an adhoc network (like > > for connection sharing). If it can't find an intersection between an > > internal "safe" frequency list and what the card supports (which it > > wouldn't be able to with this patch), it will simply use 2462 or 5180 > > MHz. > > > > Thus, I don't think you'll *break* anything specifically, but this patch > > would cause the default frequency for an IBSS created by NM to move > > from channel 1 to channel 11. > > In that case, let's just drop the patch, I have no problem with that. > > We just couldn't figure out why some channels were missing in iwlist > when they were in iw, but that's due to the 32 channel limit. Since most > people probably don't use this particular functionality, I guess it > doesn't really matter. Eventually NM should just use nl80211, or at > least try to, because there it gets more information like "cannot do > IBSS on channel XY", something that wext doesn't give you, but mac80211 > enforces. Yup; nl80211 is the way to go here. Or better yet, make wpa_supplicant card capabilities over D-Bus so NM doesn't have to touch the driver directly. Dan