From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754040Ab0AGVNV (ORCPT ); Thu, 7 Jan 2010 16:13:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753616Ab0AGVNU (ORCPT ); Thu, 7 Jan 2010 16:13:20 -0500 Received: from mail-fx0-f225.google.com ([209.85.220.225]:42095 "EHLO mail-fx0-f225.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753601Ab0AGVNU convert rfc822-to-8bit (ORCPT ); Thu, 7 Jan 2010 16:13:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Gg+bQCtDUuT4/rY/6PEoWyB24NeQ50NrqQ8T8wEjRyGUclOLgINmEHhrr3MDut/TeD IIVkO6sSj8nQomeNUzwd7vmsXQRImqpAlfAcKEDZx3/m+t62ZBfeKoYdT7ZnCMbyMS6B FiuQZt/ovMwFFEZXwoluQnSdCq6erIzQIcNxo= MIME-Version: 1.0 In-Reply-To: References: <1262888625.10429.23.camel@Joe-Laptop.home> Date: Thu, 7 Jan 2010 22:13:18 +0100 Message-ID: Subject: Re: [PATCH] lib/vsprintf.c: Add %pMF to format FDDI bit reversed MAC addresses From: =?ISO-8859-2?Q?Micha=B3_Miros=B3aw?= To: "Maciej W. Rozycki" Cc: Joe Perches , H Hartley Sweeten , David Miller , linux-kernel@vger.kernel.org, netdev Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2010/1/7 Maciej W. Rozycki : > On Thu, 7 Jan 2010, Joe Perches wrote: >> On Mon, 2010-01-04 at 23:43 +0000, Maciej W. Rozycki wrote: >> > The example below shows an address, and the sequence of bits or symbols >> > that would be transmitted when the address is used in the Source Address >> > or Destination Address fields on the MAC header.  The transmission line >> > shows the address bits in the order transmitted, from left to right.  For >> > IEEE 802 LANs these correspond to actual bits on the medium.  The FDDI >> > symbols line shows how the FDDI PHY sends the address bits as encoded >> > symbols. >> > >> >         MSB:            35:7B:12:00:00:01 >> >         Canonical:      AC-DE-48-00-00-80 >> >         Transmission:   00110101 01111011 00010010 00000000 00000000 00000001 >> >         FDDI Symbols:   35 7B 12 00 00 01" >> > >> > Please note that this address has its group bit clear. >> > >> >  This notation is also defined in the "FDDI MEDIA ACCESS CONTROL-2 >> > (MAC-2)" (X3T9/92-120) document although that book does not have a need >> > to use the MSB form and it's skipped. >> >> Adds 56 bytes to object size >> >> New: >> $ size lib/vsprintf.o >>    text          data     bss     dec     hex filename >>    8714             0       2    8716    220c lib/vsprintf.o >> old: >> $ size lib/vsprintf.o >>    text          data     bss     dec     hex filename >>    8658             0       2    8660    21d4 lib/vsprintf.o > >  What's the gain?  I'd be rather conservative when taking everybody's 56 > bytes for one or two drivers hardly anybody uses.  The format of MAC > addresses is unlikely to change, so I'd say the sources can live with > one or two places where the strings are formatted manually.  Even if the > drivers lose more than these 56 bytes. Maybe this can be Kconfig-selected by the relevant drivers then? BTW, the gain is of course consistency and code readability. Best Regards, Micha³ Miros³aw