Re: [PATCH] i2c: smbus: Log (LP)DDR5 type specific unimplemented message in `i2c_register_spd()`

From: Thomas Weißschuh
Date: Thu May 30 2024 - 16:01:21 EST


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@xxxxxxxxxxxx/