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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 73E71CAC59A for ; Wed, 17 Sep 2025 11:54:07 +0000 (UTC) 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=bpWeEr6jhoPJjA92y7DF1fUa14367p9wo3V/fiqnMPk=; b=H0FdHuCBBmA6EIswkjCnm8D3Q9 nh5DfA2LBnQR9zRpxU1U+02PkWZIGyIXK3WGqdgA3DRB8kDHc69w46y43yO2DD0lQQvtX77ctPCz6 he1rG0GNJSQreQzoiibt4tGave+l3rNkkIGSaScLuFd4eTFjEUx7sT9EdP9cLCOFEyDnXIooFq73L XmQVsO1fG6xjWYEHesAy8eIVRA7Kk95tnhgqVSI3FFTI5O/ckvIFdiRsQknVUc+fPyRB0nXNgMMIV SnyaXDAAODwOYNI6U8RHw6PtSfF+4gEBoyJhrZcksNcsoq9tDN4GkKs8RAJlYRELAfK7brOXtgGmp AVQoazxw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyqjc-0000000BCBq-4AAk; Wed, 17 Sep 2025 11:54:04 +0000 Received: from bali.collaboradmins.com ([148.251.105.195]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyqjY-0000000BC9P-3FTa; Wed, 17 Sep 2025 11:54:02 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1758110038; bh=gi4OziqmeqkoXsQcp7NMfSD4b7MAu5D/AiyhtslgU+k=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=A77T/z21aH402bY6G6mCyLiy0Mc5p8WVI0s1d3ShvSei79Fh+v5o9xgdhp+tTQCP7 pUW22EagPett90K0MFdM+hQ2ldlUMaI33pKF2BQrD1zVbRFNU/JSd5vhka8Kd2+RTy erxlmd4nN9xe3Yone+fjYsgcbt+SBmNQ7A+5aMQndk0ee/vjjsR2/2Z8s7bkEAWmMp 6gXv0y4xJ2HyWPkoL0hyMmS2YXFtOBTw87+NAeAr0wPxtJF+S/p/j6P8e7YpIYsWos SfG4hoVADGpYhLIEys0UZQQufiROflCStuTDwKfnLyFN5Gar6x0fZJ71KlokRQU8if iSh0YeSp9uphQ== Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id B1FC217E0A49; Wed, 17 Sep 2025 13:53:57 +0200 (CEST) Message-ID: <9d895847-9dd8-45e4-bc3f-a27e80371836@collabora.com> Date: Wed, 17 Sep 2025 13:53:57 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] arm64: dts: mediatek: mt7622: add 'serial' cell to efuse To: Daniel Golle Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Matthias Brugger , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org References: <18af6977cc34de75e64279141dee69dcbc81c420.1758063737.git.daniel@makrotopia.org> <87179c9f-cc7f-446f-9e8d-c84bddb48660@collabora.com> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250917_045400_977587_5EB129BF X-CRM114-Status: GOOD ( 23.75 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Il 17/09/25 12:08, Daniel Golle ha scritto: > On Wed, Sep 17, 2025 at 11:06:13AM +0200, AngeloGioacchino Del Regno wrote: >> Il 17/09/25 01:05, Daniel Golle ha scritto: >>> The efuse of the MediaTek MT7622 contains an 8-byte unique identifier. >>> Add a 'serial' cell covering those 8 bytes to the nvmem defininition of >>> the efuse to allow easy access from userspace, eg. to generate a >>> persistent random MAC address on boards like the BananaPi R64 which >>> doesn't have any factory-assigned addresses. >> >> Sorry, but I don't get why this is named "serial" and not "soc-uuid". >> >> Care to explain? > > I don't have documentation covering the efuse content but only got this > information on an informal way: > > https://forum.banana-pi.org/t/bpi-r3-serial-number/14556/10?u=dangowrt > > Either name is fine with me, I thought of it as "serial number", but > obviously "soc-uuid" works fine, too. > I can change it to that and send v2 tonight. > Aaaaaah that's why "serial", okay - I got confused because the eFuses contain many "calibration data" entries, and that triggered me to think that it could be a "serial calibration data" entry. After reading the commit description it became very clear that the initial impression was wrong, but then still, when reading the devicetree without having the description of the commit introducing that, it's easy to get confused again. In any case, well, it could be a serial number, or it could be a randomly generated UUID - but since we don't know, I think that calling this "serial-no" may actually be wrong anyway. We can escape this uncertainty though: a serial number is supposed to be unique, and it is used as an identifier (which identifies one, or multiple aspects, either an increasing number for chip number, or one that says the production date and chip number). Seeing it like this, calling it "soc-uuid" identifies this array as containing a number that uniquely identifies the chip, be it a serial number or a randomly generated number. In case you find out sure information that this is really a serial number (which doesn't really look right, it's too many bytes, but you never know) you can always come back later and add a comment in DT saying that it is just.. that. For now, let's go with soc-uuid :-) So please, change the name to soc-uuid on all four commits, after which, feel free to add my Reviewed-by: AngeloGioacchino Del Regno to all four commits. Cheers, Angelo