From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE74F1F1311; Fri, 25 Jul 2025 07:09:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.207.212.93 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753427401; cv=none; b=ECdUs7knAHm7spQhDcGBcc+sShbhTD+zxPRMiMArW5KHazdQ2w3GxMv8Cm0dQx2KSi/Ddym8S6p4+bHEC8v2zIuZXhtAVrjCeOJuiJr8rVWOPLLIoXOFu2NvaFhUo0vS3lFobTrN+pkKyRAbLvAQGala3uXvj0BkCK6aXRrh334= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753427401; c=relaxed/simple; bh=JL30bk1jn1jV9pISqgo+bWdb/5RDGbJ7aIr53ikjD6E=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=PAkZSrYxsD+3hLDT9Jwz6D0ULPbNJkscx9VakEkk/BQHphQOeGFJm56lDthZ4SCzgGewLz5hc3nDbm6PYPj28yYWOGXpGB0+2LNVjzN7upfz+DZP987mNBhq5Xq8lLUMV6dw53zA8zU1Wm9gCWEvJiEZCRCX43xP7BskAC/isG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.st.com; spf=pass smtp.mailfrom=foss.st.com; dkim=pass (2048-bit key) header.d=foss.st.com header.i=@foss.st.com header.b=vEY7oeG+; arc=none smtp.client-ip=91.207.212.93 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.st.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foss.st.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=foss.st.com header.i=@foss.st.com header.b="vEY7oeG+" Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 56P61XZi009176; Fri, 25 Jul 2025 09:09:25 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=selector1; bh= LzqH02+hJ/0E8n+RTM+yEwFitfKa/gSQdkGVRRTXJhc=; b=vEY7oeG+pNnop6/X Y9urlffHn9wPzkQ2Is/FDs6FmFPNXT3zTb3jyMz3lmY7QPMwpHHlMXBmXHaer/PU 0K0P0ulWgakiEqWGw1l11dPWR/0Is+mSEQnefGwkZ3l/7cXUl6SA3HJ2CRdoyG1I FdmL8tUHYqCtB98XPDPWNBGYyLXEwDmWXM7P+PtbfkAkPayNHbYAgdZ3XfNJ2Zbc CmgC/QaDxklOmCvKhJ7nMI4NpBlPKOB2X2y39VEgc7AEaz1kO+m3wWAhQP0OsPLr FY38beWUv0pV94PWCAt8crCejpNCdBfw4cLvaHFaeaNLHLfxgTQP0XVsBJXJZTO6 L/feBQ== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 483w5rsn0e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 25 Jul 2025 09:09:24 +0200 (MEST) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 4812F40044; Fri, 25 Jul 2025 09:07:57 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node2.st.com [10.75.129.70]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 8B10578175F; Fri, 25 Jul 2025 09:06:35 +0200 (CEST) Received: from [10.48.86.185] (10.48.86.185) by SHFDAG1NODE2.st.com (10.75.129.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 25 Jul 2025 09:06:34 +0200 Message-ID: Date: Fri, 25 Jul 2025 09:06:33 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 05/20] dt-bindings: memory: factorise LPDDR props into SDRAM props To: Julius Werner CC: Will Deacon , Mark Rutland , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue , Philipp Zabel , Jonathan Corbet , Gatien Chevallier , Michael Turquette , Stephen Boyd , Gabriel Fernandez , Krzysztof Kozlowski , Le Goffic , , , , , , , References: <20250723-ddrperfm-upstream-v4-0-1aa53ca319f4@foss.st.com> <20250723-ddrperfm-upstream-v4-5-1aa53ca319f4@foss.st.com> <204401b4-b483-47e2-ae73-0994b39bd30c@foss.st.com> Content-Language: en-US From: Clement LE GOFFIC In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SHFCAS1NODE2.st.com (10.75.129.73) To SHFDAG1NODE2.st.com (10.75.129.70) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-07-25_02,2025-07-24_01,2025-03-28_01 Hi Julius, On 7/25/25 00:33, Julius Werner wrote: >>> I don't think this will identify a part unambiguously, I would expect >>> the DDR revision ID to be specific to the part number. (In fact, we're >>> also not sure whether manufacturer+revision identifies LPDDR parts >>> unambiguously for every vendor, we just didn't have anything more to >>> work with there.) I would suggest to use either `ddrX-YYYY,AAA...,ZZ` >>> or `ddrX-YYYY,ZZ,AAA...` (where AAA... is the part number string from >>> SPD 329-348 without the trailing spaces). The first version looks a >>> bit more natural but it might get confusing on the off chance that >>> someone uses a comma in a part number string. >> >> The first one seems better indeed. >> If the manufacturer put a comma in the part number we should handle it >> at a software level to me and if it is a devicetree error it is up to >> the devicetree writer to fix it. >> What do you think ? I meant exactly what you are stating below :-) > > Not sure what you mean by "handle it at a software level"? Using comma > characters in the part number is not illegal according to the SPD > spec, as far as I can tell. > > That said, it is still possible to disambiguate this as long as the > revision number is always there, you just have to look for the last > comma from the end (so e.g. the string `ddr4-1234,some,part,567,89` > could be unambiguously parsed as manufacturer ID 0x1234, part number > `some,part,567` and revision ID 0x89, the parsing code just needs to > be a bit careful). So maybe this is not actually a problem. Best regards, Clément