From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:54598 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752802Ab1EIQxX (ORCPT ); Mon, 9 May 2011 12:53:23 -0400 Message-ID: <4DC81BFB.3020103@candelatech.com> (sfid-20110509_185326_799595_5D5F28BA) Date: Mon, 09 May 2011 09:53:15 -0700 From: Ben Greear MIME-Version: 1.0 To: Johannes Berg CC: "John W. Linville" , linux-wireless Subject: Re: [PATCH] cfg80211: restrict AP beacon intervals References: <1304959275.12202.4.camel@jlt3.sipsolutions.net> <4DC81A61.9080101@candelatech.com> <1304959783.12202.7.camel@jlt3.sipsolutions.net> In-Reply-To: <1304959783.12202.7.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 05/09/2011 09:49 AM, Johannes Berg wrote: > On Mon, 2011-05-09 at 09:46 -0700, Ben Greear wrote: >> On 05/09/2011 09:41 AM, Johannes Berg wrote: >>> From: Johannes Berg >>> >>> Multiple virtual AP interfaces can currently try >>> to use different beacon intervals, but that just >>> leads to problems since it won't actually be done >>> that way by drivers. Return an error in this case >>> to make sure it won't be done wrong. >> >> I think there is no problem with having different beacon >> intervals, as long as they are all a multiple of >> the smallest interval and the driver does things properly. >> >> I'm not sure ath9k or ath5k currently supports this properly, >> but there was a patch floating around for a while that did >> this for ath9k I think... > > Yes, in theory that's possible, but apparently no driver actually did > this correctly. Also, it didn't seem like anyone really cares, and we > need to enforce some restrictions because otherwise drivers will end up > doing it wrong, and you'll end up having a beacon interval of 200 while > advertising 150 for example, which will totally throw off powersaving > clients. > > If you really care greatly about having different beacon intervals (and > I don't see why you would?) then maybe you can think how we can enforce > and advertise that to userspace. For now, I'm more comfortable just > restricting it. I guess we could add a flag to the driver when it supports it properly and modify your logic to check for even multiples instead of just == if that flag is set? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com