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Date: Thu, 30 May 2024 22:01:06 +0200
From: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <thomas@t-8ch.de>
To: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>, 
	Jean Delvare <jdelvare@suse.de>, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: smbus: Log (LP)DDR5 type specific unimplemented
 message in `i2c_register_spd()`
Message-ID: <66acde9a-b453-465d-8b44-2bfc2164cdbb@t-8ch.de>
References: <20240530183444.9312-2-pmenzel@molgen.mpg.de>
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On 2024-05-30 20:34:43+0000, Paul Menzel wrote:
> On several systems Linux logs:
> 
>      i2c i2c-0: Memory type 0x22 not supported yet, not instantiating SPD
> 
> 1.  Supermicro Super Server/X13SAE, BIOS 2.0 10/17/2022
> 2.  Dell Inc. Precision 3660/0PRR48, BIOS 2.9.3 11/22/2023
> 3.  Dell Inc. OptiPlex SFF Plus 7010/0YGWFV, BIOS 1.7.1 08/11/2023
> 4.  Run `git grep 'emory type.*supported yet, not instantiating SPD'` in
>     the repository of dmesg reports for various computers collected by
>     Linux users at https://linux-hardware.org. [1]
> 
> Add 0x22 and 0x23 as memory types for DDR5 according to section 7.18.2
> (Memory Device — Type), table 78 in *System Management BIOS (SMBIOS)
> Reference Specification*, version 3.6.0 [2]. These use JEDEC JESD300-5 for
> SPD, and, currently, no driver exists, so add a specific warning for this
> case.

There is a SPD5118 driver coming up, which will handle DDR5 chips [0].

[0] https://lore.kernel.org/lkml/20240529205204.81208-1-linux@roeck-us.net/