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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 75061C433ED for ; Tue, 13 Apr 2021 00:56:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5663A6124C for ; Tue, 13 Apr 2021 00:56:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239118AbhDMA4u (ORCPT ); Mon, 12 Apr 2021 20:56:50 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:47030 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238450AbhDMA4u (ORCPT ); Mon, 12 Apr 2021 20:56:50 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1lW7LN-00GOEl-SK; Tue, 13 Apr 2021 02:55:53 +0200 Date: Tue, 13 Apr 2021 02:55:53 +0200 From: Andrew Lunn To: Michael Walle Cc: ath9k-devel@qca.qualcomm.com, UNGLinuxDriver@microchip.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-renesas-soc@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-amlogic@lists.infradead.org, linux-oxnas@groups.io, linux-omap@vger.kernel.org, linux-wireless@vger.kernel.org, devicetree@vger.kernel.org, linux-staging@lists.linux.dev, Gregory Clement , Sebastian Hesselbarth , Russell King , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Andreas Larsson , "David S . Miller" , Jakub Kicinski , Maxime Ripard , Chen-Yu Tsai , Jernej Skrabec , Joyce Ooi , Chris Snook , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , bcm-kernel-feedback-list@broadcom.com, Florian Fainelli , Nicolas Ferre , Claudiu Beznea , Sunil Goutham , Fugang Duan , Madalin Bucur , Pantelis Antoniou , Claudiu Manoil , Li Yang , Yisen Zhuang , Salil Mehta , Hauke Mehrtens , Thomas Petazzoni , Vadym Kochan , Taras Chornyi , Mirko Lindner , Stephen Hemminger , Felix Fietkau , John Crispin , Sean Wang , Mark Lee , Matthias Brugger , Bryan Whitehead , Vladimir Zapolskiy , Sergei Shtylyov , Byungho An , Kunihiko Hayashi , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Kevin Hilman , Neil Armstrong , Jerome Brunet , Martin Blumenstingl , Vinod Koul , Nobuhiro Iwamatsu , Grygorii Strashko , Wingman Kwok , Murali Karicheri , Michal Simek , Radhey Shyam Pandey , Kalle Valo , Lorenzo Bianconi , Ryder Lee , Stanislaw Gruszka , Helmut Schaa , Heiner Kallweit , Rob Herring , Frank Rowand , Greg Kroah-Hartman , =?iso-8859-1?B?Suly9G1l?= Pouiller , Vivien Didelot , Vladimir Oltean Subject: Re: [PATCH net-next v4 1/2] of: net: pass the dst buffer to of_get_mac_address() Message-ID: References: <20210412174718.17382-1-michael@walle.cc> <20210412174718.17382-2-michael@walle.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210412174718.17382-2-michael@walle.cc> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Mon, Apr 12, 2021 at 07:47:17PM +0200, Michael Walle wrote: > of_get_mac_address() returns a "const void*" pointer to a MAC address. > Lately, support to fetch the MAC address by an NVMEM provider was added. > But this will only work with platform devices. It will not work with > PCI devices (e.g. of an integrated root complex) and esp. not with DSA > ports. > > There is an of_* variant of the nvmem binding which works without > devices. The returned data of a nvmem_cell_read() has to be freed after > use. On the other hand the return of_get_mac_address() points to some > static data without a lifetime. The trick for now, was to allocate a > device resource managed buffer which is then returned. This will only > work if we have an actual device. > > Change it, so that the caller of of_get_mac_address() has to supply a > buffer where the MAC address is written to. Unfortunately, this will > touch all drivers which use the of_get_mac_address(). > > Usually the code looks like: > > const char *addr; > addr = of_get_mac_address(np); > if (!IS_ERR(addr)) > ether_addr_copy(ndev->dev_addr, addr); > > This can then be simply rewritten as: > > of_get_mac_address(np, ndev->dev_addr); > > Sometimes is_valid_ether_addr() is used to test the MAC address. > of_get_mac_address() already makes sure, it just returns a valid MAC > address. Thus we can just test its return code. But we have to be > careful if there are still other sources for the MAC address before the > of_get_mac_address(). In this case we have to keep the > is_valid_ether_addr() call. > > The following coccinelle patch was used to convert common cases to the > new style. Afterwards, I've manually gone over the drivers and fixed the > return code variable: either used a new one or if one was already > available use that. Mansour Moufid, thanks for that coccinelle patch! > > > @a@ > identifier x; > expression y, z; > @@ > - x = of_get_mac_address(y); > + x = of_get_mac_address(y, z); > <... > - ether_addr_copy(z, x); > ...> > > @@ > identifier a.x; > @@ > - if (<+... x ...+>) {} > > @@ > identifier a.x; > @@ > if (<+... x ...+>) { > ... > } > - else {} > > @@ > identifier a.x; > expression e; > @@ > - if (<+... x ...+>@e) > - {} > - else > + if (!(e)) > {...} > > @@ > expression x, y, z; > @@ > - x = of_get_mac_address(y, z); > + of_get_mac_address(y, z); > ... when != x > > > All drivers, except drivers/net/ethernet/aeroflex/greth.c, were > compile-time tested. > > Suggested-by: Andrew Lunn > Signed-off-by: Michael Walle I cannot say i looked at all the changes, but the ones i did exam seemed O.K. Reviewed-by: Andrew Lunn Andrew