linux-kernel - Re: [PATCH v2 3/7] firmware: dmi: Read additional information when decoding DMI table

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Message-ID: <329d3e941ddcf7f594bcba23ffef18cd3c610293.camel@suse.com>
Date: Mon, 22 Dec 2025 22:31:13 +0100
From: Jean DELVARE <jdelvare@...e.com>
To: "Mario Limonciello (AMD)" <superm1@...nel.org>, Yazen Ghannam
	 <yazen.ghannam@....com>, x86@...nel.org
Cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "H . Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/7] firmware: dmi: Read additional information when
 decoding DMI table

Hi all,

On Tue, 2025-12-16 at 06:33 -0600, Mario Limonciello (AMD) wrote:
> Type 40 entries (Additional information) are summarized in section
> 7.41 as part of the SMBIOS specification.  Save these entries when
> decoding the DMI tables.
> 
> Signed-off-by: Mario Limonciello (AMD) <superm1@...nel.org>
> ---
> v2:
>  * Drop some unneeded variables (LKP robot)
>  * Allow any length strings, not just 5 and longer
> --- (...)

Having read the whole series now, my conclusion is that we don't want
to do that. The way AMD is storing this string in a type 40 record is
absolutely not how these records are supposed to be used. So having
generic code to store and retrieve strings from type 40 records is
neither needed nor desirable.

This is a hack from AMD, the best way to deal with it is with the
minimum amount of code in the kernel and smallest memory footprint.
Simply catch the string when you see it, log it, and be done with it.

Thanks,
-- 
Jean Delvare
SUSE L3 Support