From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8718CC43465 for ; Sun, 20 Sep 2020 01:22:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50B16208B8 for ; Sun, 20 Sep 2020 01:22:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726817AbgITBWa (ORCPT ); Sat, 19 Sep 2020 21:22:30 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:45692 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726707AbgITBW3 (ORCPT ); Sat, 19 Sep 2020 21:22:29 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kJo3U-00FRHl-F7; Sun, 20 Sep 2020 03:22:16 +0200 Date: Sun, 20 Sep 2020 03:22:16 +0200 From: Andrew Lunn To: ansuelsmth@gmail.com Cc: 'Miquel Raynal' , 'Richard Weinberger' , 'Vignesh Raghavendra' , 'Rob Herring' , "'David S. Miller'" , 'Jakub Kicinski' , 'Heiner Kallweit' , 'Russell King' , 'Frank Rowand' , 'Boris Brezillon' , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: R: [PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment Message-ID: <20200920012216.GE3673389@lunn.ch> References: <20200919223026.20803-1-ansuelsmth@gmail.com> <20200919223026.20803-5-ansuelsmth@gmail.com> <20200920003128.GC3673389@lunn.ch> <006301d68ee6$87fcc400$97f64c00$@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <006301d68ee6$87fcc400$97f64c00$@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Sep 20, 2020 at 02:39:39AM +0200, ansuelsmth@gmail.com wrote: > > > > -----Messaggio originale----- > > Da: Andrew Lunn > > Inviato: domenica 20 settembre 2020 02:31 > > A: Ansuel Smith > > Cc: Miquel Raynal ; Richard Weinberger > > ; Vignesh Raghavendra ; Rob Herring > > ; David S. Miller ; Jakub > > Kicinski ; Heiner Kallweit ; > > Russell King ; Frank Rowand > > ; Boris Brezillon ; linux- > > mtd@lists.infradead.org; devicetree@vger.kernel.org; linux- > > kernel@vger.kernel.org; netdev@vger.kernel.org > > Oggetto: Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac- > > address-increment > > > > > + mac-address-increment: > > > + description: > > > + The MAC address can optionally be increased (or decreased using > > > + negative values) from the original value readed (from a nvmem > cell > > > > Read is irregular, there is no readed, just read. > > > > > + for example). This can be used if the mac is readed from a > dedicated > > > + partition and must be increased based on the number of device > > > + present in the system. > > > > You should probably add there is no underflow/overflow to other bytes > > of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > > > > > + minimum: -255 > > > + maximum: 255 > > > + > > > + mac-address-increment-byte: > > > + description: > > > + If 'mac-address-increment' is defined, this will tell what byte > of > > > + the mac-address will be increased. If 'mac-address-increment' is > > > + not defined, this option will do nothing. > > > + default: 5 > > > + minimum: 0 > > > + maximum: 5 > > > > Is there a real need for this? A value of 0 seems like a bad idea, > > since a unicast address could easily become a multicast address, which > > is not valid for an interface address. It also does not seem like a > > good idea to allow the OUI to be changed. So i think only bytes 3-5 > > should be allowed, but even then, i don't think this is needed, unless > > you do have a clear use case. > > > > Andrew > > Honestly the mac-address-increment-byte is added to give user some control > but I > don't really have a use case for it. Should I limit it to 3 or just remove > the function? If you have no use case, just remove it and document that last byte will be incremented. I somebody does need it, it can be added in a backwards compatible way. Andrew