Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933039Ab1EMNXg (ORCPT ); Fri, 13 May 2011 09:23:36 -0400 Received: from p15132773.pureserver.info ([217.160.209.225]:39810 "EHLO smtp.chost.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932909Ab1EMNXf (ORCPT ); Fri, 13 May 2011 09:23:35 -0400 X-Greylist: delayed 401 seconds by postgrey-1.27 at vger.kernel.org; Fri, 13 May 2011 09:23:35 EDT Cc: linux-wireless , devel , John@xo15-sascha.sascha.silbe.org, W.Linville@xo15-sascha.sascha.silbe.org, , libertas-dev , netdev , linux-kernel Subject: Re: [PATCH] Add libertas_disablemesh module parameter to disable mesh interface To: Dan Williams In-reply-to: <1305169898.8054.19.camel@dcbw.foobar.com> References: <1305118354-17337-1-git-send-email-silbe@activitycentral.com> <1305169898.8054.19.camel@dcbw.foobar.com> Date: Fri, 13 May 2011 15:16:31 +0200 Message-Id: <1305290935-sup-4547@xo15-sascha.sascha.silbe.org> User-Agent: Sup/git Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Sascha Silbe Content-Type: multipart/signed; boundary="=-1305292607-266040-1562-3202-9-="; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2698 Lines: 66 --=-1305292607-266040-1562-3202-9-= Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Excerpts from Dan Williams's message of Thu May 12 05:11:36 +0200 2011: > On Wed, 2011-05-11 at 14:52 +0200, Sascha Silbe wrote: > > This allows individual users and deployments to disable mesh support = at > > runtime, i.e. without having to build and maintain a custom kernel. > Does the mesh interface somehow cause problems, even when nothing is > using it? Some people suspect it does, but there's no hard data showing that. But then the problems are often hard to reproduce in the first place, so proving a correlation with mesh is even harder. The hardware based mesh support is based on an outdated draft of 802.11s and not interoperable with any other device AFAIK. For most users Ad-hoc networks are the better option. Disabling mesh support as low-level as possible makes it less likely that any remains are causing trouble. With at least four layers (firmware, kernel, NM, Sugar) involved in managing connectivity and one of the (firmware) being closed source, I prefer to simplify things by eliminating three layers for functionality we don't intend to use. It makes debugging (and blaming ;) ) a lot easier. In the field, mesh support is currently disabled using /sys/class/net/eth0/lbs_mesh. However, it comes back after resume (possibly only if powercycled) and needs to be disabled again by post-resume hacks. Race conditions with NM are possible. A user space option would be to teach NM to disable mesh support (at runtime - we don't want to ship a custom NM package). I'd expect the patch to be much more invasive than the one posted for libertas. Sascha -- = http://sascha.silbe.org/ http://www.infra-silbe.de/ --=-1305292607-266040-1562-3202-9-= Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.0beta1 (GNU/Linux) iQEcBAEBCgAGBQJNzS8vAAoJELpz82VMF3Da94UH/Rluny57CQsZHDC+3ykgWRnc +1LkVmBqZBDElLmRCsoPU2qPje2V6Hs+f17/GSHiYS3xVRCG7jgkFv5d27ix2b+L s6sSk4up44PZD39uLsquDZjgXlOKLHbISRsClbzh0C8d65o5LweJTot67q1lY3Qu Q3jheEgkoFzLwePxiGRqKW0i5o0pGCPlPcS7fzn2kyhPxOD/f6FPncGSv9o9iPdB UAoSr+QvbQWtCAuOjOzdJsOPWInNr566jhpchi0i9UUChdTs4MjH9SKSVh15qaOg XCYhXngwJqfMXbpr5++SF2SMd32Vk62uLNId9XxTf1GKuTOoebf2a5DzGZ89sqs= =C+AO -----END PGP SIGNATURE----- --=-1305292607-266040-1562-3202-9-=-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/