From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (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 8F744171A5; Sat, 1 Jun 2024 19:23:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.22 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717269831; cv=none; b=KKjJZVfx7XUhoxk1qZmiOxlzix/7m33GuAEAefEzUwp8+kqf0ZQQRB2LYVqaq+x8gsVKcvTn7qhtckTPAxstdE7nOVndJRJCjIKzJTYvRd5Sg/UBq25cKVgZGthjyTlDxIMBpyY9H5DXmP0kFrcqTErtCvmyoA1qdXUg8ohRDU8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717269831; c=relaxed/simple; bh=An57snNAVWPM/Jd6dWaMAbWr+p4o459kcQwDlqhWjdY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UgXHsraHarcNeOmdr5F9/LyVsb0ms+uckpEzx6r8p/2n54jEJv7VTLDYkVX9TQI/vajY7lxylogSBW5/O8Jxo8a18ngmZDsKPMbRwDa6vwszBJqAkHoINYsckgYSlSEy8pJTBx8r85fKXb1Y62v6Q4mfRdRF8jaCtIV5l7l9GjE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.de; spf=pass smtp.mailfrom=gmx.de; dkim=pass (2048-bit key) header.d=gmx.de header.i=w_armin@gmx.de header.b=Pxy2MPUV; arc=none smtp.client-ip=212.227.17.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.de header.i=w_armin@gmx.de header.b="Pxy2MPUV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.de; s=s31663417; t=1717269804; x=1717874604; i=w_armin@gmx.de; bh=5iWYMGr3Z9QM/GtgZJ3Kx+3BmVGKNlOjqb+ZMe0xvfE=; h=X-UI-Sender-Class:Message-ID:Date:MIME-Version:Subject:To:Cc: References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding:cc:content-transfer-encoding: content-type:date:from:message-id:mime-version:reply-to:subject: to; b=Pxy2MPUVGWr3hijaYDg/yx1eCUZ9XaIp1jHq4pcGIDiAY8nnzky8HkrWsssXC71v 0hLevXvTfVUhzC+mXmDZ/ndapOnZbbLTnsCKWbZrznIIVgI2ObF4pjo5W8USh+beY OP07SDy0o2a9AeOZXxeX+2+n5HOquTjyvgjtWAPO/YaIBWyUyWM6vl90dlcya8ArR tOXOVgyXrVwQttxHCUzOkWdytJTFZjR3wr8wevXaYFufzHTaRd3jJq52WwhZLajzf 3/o09pwuxc6sadBawcfuTr6E3tB4Quvmv+EWiUwdjC/KZXU3ApY9zZbv9GVyVJOVt nDDKozEw8DsCjLc5+A== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [141.30.226.129] ([141.30.226.129]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1N7zFj-1sYgGd2nLf-0183qj; Sat, 01 Jun 2024 21:23:24 +0200 Message-ID: Date: Sat, 1 Jun 2024 21:23:24 +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 RFT v3 4/4] hwmon: (spd5118) Add support for reading SPD data To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , Guenter Roeck Cc: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, =?UTF-8?Q?Ren=C3=A9_Rebe?= , Wolfram Sang References: <20240531230556.1409532-1-linux@roeck-us.net> <20240531230556.1409532-5-linux@roeck-us.net> <4cc979c3-3ce0-4f31-b5d0-508e1af5fdf4@roeck-us.net> <4e4341e4-2165-40d4-909c-9d5164e97942@t-8ch.de> Content-Language: en-US From: Armin Wolf In-Reply-To: <4e4341e4-2165-40d4-909c-9d5164e97942@t-8ch.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:nl2ZL9DzOWscLAZzj4pxS/2xcRN7csMsdJN5BXRyQHPcES/oX5C 5EyHI0SM2GwJ5CWiFINrMGy3U5/t7pEC5MR0GsaNLbrto7Bjk88Jdeb5saIFubD1f8T4uh2 HgBvkgPuy2yALqZQSbmmU7oAxQxGXV0S3/xhXcVDJWH2QyfPzMZAAS8qMo7s9KxMReMI5IE iRDGNHfWPH1i/Y2+4avQg== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:RocisHFiDs0=;xJvP+AsNP0agfOEdM+8EpcR+hG5 AoQMzvgYdj6NbdSYzdVZTCSlnP0bdUrEe7k3yBAQx6dCBZMpGaFIMnbp5Iratzzxbp3Ahf2YU 41+LqTduQDJm2oRRtcemp149WflnkjYtW/nVZDUu2bwkuSz5r5wK0KmrhghH8LATAb9z3BIs4 ImQ9Nv7SqyBPP6VA2zYphJgORMSbEotG7lhhz2k9ROQc2iU40/k+sJt0QSsc56dnnJNt159/c feB07tytFp3BVZ7fa64SIepA3rVjOoHSHerrWyuv71+IGJp0ziSwKe7CMl2/yhUHzG/h4NmvV KohmjJxzgc21/lRaVgtz07vEV8zzvDuaS5KV8h8GG/vMeGbgUhJ39zFTKfwCazQj7ZRoUy3Q2 7JEXrUaCvO4LkgcAGID+DcN4PreR6LYzeFkRE9XlLLjekT4zOPAxT1bpSa6zwaC/Sb6ewehY0 pxkngSnN1wGCGtdZf2vBo14xH4UupqdDzpwg6sBSpesKjQCxIS+11ieM6iMOhJc2zRTgEjwhL Qh2A2I4WR7WSP/khom2jbXR01X7nkLf5/MuQ8W3I3WMmH9acxeP3IrCDsxjHIgwxQ+Jhask4f JRy9HWgjN2oTMuBSVvoouhY3pOuRv7pnxzbLFKMFbGh5swdtFZxEYlmWlaqEBZM+lHqEIKXai 69WRtDPhGP1Y9VdzIyLGvklNSeuh6tXUWALuOPx6l81MR1OPnAsiJIwZwD37DVgrUz130AygH mgHnlfvKjaf+XtsKEw3Q1aQ/Rl1Kg6j6hT6YwAZ//ClBkLURNcKXgTyTFMVpONTdZ/uofuRcv 7bufuvG+4BJDiRawbSMwM44V6/LmEvhFc5ko2FrJH3v/g= Am 01.06.24 um 16:08 schrieb Thomas Wei=C3=9Fschuh: > On 2024-06-01 06:48:29+0000, Guenter Roeck wrote: > > > >> Makes sense. Another question: >> >> This: >> >> + struct nvmem_config nvmem_config =3D { >> + .type =3D NVMEM_TYPE_EEPROM, >> + .name =3D dev_name(dev), >> + .id =3D NVMEM_DEVID_AUTO, >> >> results in: >> >> $ ls /sys/bus/nvmem/devices >> 0-00501 0-00512 0-00523 0-00534 cmos_nvram0 >> ^^^^^^^ ^^^^^^^ ^^^^^^^ ^^^^^^^ >> >> which really doesn't look good. My current plan is to go with NVMEM_DEV= ID_NONE, >> which results in >> >> $ ls /sys/bus/nvmem/devices >> 0-0050 0-0051 0-0052 0-0053 cmos_nvram0 >> >> We could also used fixed strings, but "spd" results in "spd[1-4]" which >> I think would be a bit misleading since the DDR3/4 SPD data format is >> different, and "spd5118" would result in "spd5118[1-4]" which again wou= ld >> look odd. Any suggestions ? > In order of descending, personal preference: > > * spd-ddr5-[0-3] (.id =3D client->address - 0x50) Hi, this will break as soon as more than 8 DDR5 DIMMs are installed. > * spd-ddr5-[0-3] (NVMEM_DEVID_AUTO) > * Same with only "ddr5-" > * spd5118-[0-3] > * Your proposal from above > * nvmem[0-3] (default handling) > * 0-0050-[0-3] > > Also can't a user of the eeprom already figure out which kind of module > it is by looking at the eeprom contents? > The first few bytes used for that seem to be compatible between at least > DDR4 and DDR5. > > So using plain spd[1-4] could be enough. This could cause problems when DDR6 arrives. Personally i would prefer the spd5118-X (NVMEM_DEVID_AUTO) format. Thanks, Armin Wolf