From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 12 Sep 2023 14:35:48 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qg2cP-00CdTM-HZ for lore@lore.pengutronix.de; Tue, 12 Sep 2023 14:35:48 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qg2cN-00050I-JL for lore@pengutronix.de; Tue, 12 Sep 2023 14:35:48 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=bZhm3X3bo/IOCjPCiSGdVCAFKjxVVeL+qZtEq2UsRZ0=; b=O7T8kmvSxNIlVXlDxfbVZBCXgz Y2LMmfad80hihys16ndHl9w0cyJ/k8GeJym+dQA3rD7yJUt0KqnpBzWxQOLr9hXFdIpPzuZAy0BMm 7ttwOB8MVF1xhoyT4J2auAOd46q+U+lcjNxWIjVon1IBCro5REBiMvaxvYHV6IUwELmI7Cyia+rKl xT3u+pmOOsSKFaHkItfrEAIlDFnCuN3i9hB9Xgi8anPesdAgs85CbX6UN+/PA5KWlhgNT7sdK//1L pVegadbGqysBXDHLQCuOlSZ/yLxn9+KvQNYhXdLEXz9Q3jb3Vb/TqQGvXrpQNDnNWe0KDagJ1us34 oraIvYdg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qg2bB-003LHY-0u; Tue, 12 Sep 2023 12:34:33 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qg2b7-003LH6-2o for barebox@lists.infradead.org; Tue, 12 Sep 2023 12:34:31 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1qg2b6-0004lC-EB; Tue, 12 Sep 2023 14:34:28 +0200 Message-ID: <87e96b20-ae2c-9679-29e4-1c54ee24948a@pengutronix.de> Date: Tue, 12 Sep 2023 14:34:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Content-Language: en-US To: Sascha Hauer Cc: barebox@lists.infradead.org, Alexander Shiyan References: <20230911155927.3786335-1-a.fatoum@pengutronix.de> <20230911155927.3786335-3-a.fatoum@pengutronix.de> <20230912104903.GA637806@pengutronix.de> From: Ahmad Fatoum In-Reply-To: <20230912104903.GA637806@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230912_053429_927610_9FE73D69 X-CRM114-Status: GOOD ( 39.31 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.6 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 3/3] net: add generic MAC address derivation from machine ID X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Hi Sascha, On 12.09.23 12:49, Sascha Hauer wrote: > On Mon, Sep 11, 2023 at 05:59:27PM +0200, Ahmad Fatoum wrote: >> From: Ahmad Fatoum >> >> Especially during development, devices often lack a MAC address. While a >> MAC address can be easily added to the environment: >> >> nv dev.eth0.ethaddr="aa:bb:cc:dd:ee:ff" >> >> It's easily lost when flashing complete new images, e.g. from CI. >> Make the development experience neater by deriving a stable MAC address >> if possible. > > I like this, because my Fritzbox network overview is full of duplicate > entries coming from boards with random MAC addresses. Glad you like it. If you are ok with the first two patches, can you take those until I respin this? > > >> @@ -558,6 +559,7 @@ static int of_populate_ethaddr(void) > > This function should be renamed. When reviewing this patch I asked > myself why you limit generating a fixed MAC address to the DT case until > I realized that you actually don't. I was just confused by the function > name. Ah, didn't notice that. Will rename. > >> { >> char str[sizeof("xx:xx:xx:xx:xx:xx")]; >> struct eth_device *edev; >> + bool generated = false; >> int ret; >> >> list_for_each_entry(edev, &netdev_list, list) { >> @@ -566,11 +568,18 @@ static int of_populate_ethaddr(void) >> >> ret = of_get_mac_addr_nvmem(edev->parent->of_node, >> edev->ethaddr); >> + if (ret && IS_ENABLED(CONFIG_NET_ETHADDR_FROM_MACHINE_ID)) { > > This check doesn't seem to be needed, generate_ether_addr() already > returns -ENOSYS when this option is not enabled. Until we have LTO, I'd like to keep this in, so the function need not be called. In this instance, I find it is a less ugly alternative to have #ifdef and static inline.. >> @@ -381,9 +419,16 @@ static struct net_connection *net_new(struct eth_device *edev, IPaddr_t dest, >> >> if (!is_valid_ether_addr(edev->ethaddr)) { >> char str[sizeof("xx:xx:xx:xx:xx:xx")]; >> - random_ether_addr(edev->ethaddr); >> + >> + ret = generate_ether_addr(edev->ethaddr, edev->dev.id); > > For most network devices we won't get here because of_populate_ethaddr() > will already have done it for us. It's only used for devices that are > probed after postenvironment_initcall(), namely USB devices. Or those that don't have CONFIG_NET_ETHADDR_FROM_MACHINE_ID enabled or don't have a machine ID set. > I think this deserves a cleanup before we merge this. The original > reason to introduce a postenvironment_initcall() for getting the MAC > address from nvmem was: > >> We do this in a very late initcall, because we don't want to enforce a >> probe a probe order between nvmem providers and network devices. We >> can't do it at randomization time, because we need to fixup Ethernet mac >> addresses, even when barebox itself doesn't ifup the netdev. > > I think we should have one centralized function that retrieves the MAC > address for an ethernet device. That should be called when we actually > need that MAC address, so once in net_new() and once at of_fixup time. > > Right now the behaviour is inconsistent with regard to random MAC > addresses. Currently we propagate the random MAC address to the Linux > device tree when we use ethernet in barebox, but we don't propagate it > when we do not use ethernet in barebox. We should decide what the > desired behaviour is and do it consistently regardless if we use > ethernet in barebox or not. This could be cleaned up along the way. Randomized MAC addresses are a necessary evil when barebox needs to do networking and doesn't have a stable address. If we have a stable address, we shouldn't randomize. Fixing up a randomized MAC address is a lesser evil than having different MAC addresses for barebox and Linux. If we don't need a MAC address in barebox, we shouldn't generate a random one just to fix it up. If we have a stable address, we should tell Linux about it. That's the logic of the current code and it's sensible to me. Why change it? Cheers, Ahmad > > Sascha > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |