linux-kernel - Re: [PATCH 2/7] EDAC/mce_amd: Remove SMCA Extended Error code descriptions

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Message-ID: <20230720135950.GHZLk91jGbX7l+7AMz@fat_crate.local>
Date:   Thu, 20 Jul 2023 15:59:50 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Muralidhara M K <muralimk@....com>
Cc:     linux-edac@...r.kernel.org, x86@...nel.org,
        linux-kernel@...r.kernel.org, mingo@...hat.com, mchehab@...nel.org,
        nchatrad@....com, yazen.ghannam@....com,
        Muralidhara M K <muralidhara.mk@....com>
Subject: Re: [PATCH 2/7] EDAC/mce_amd: Remove SMCA Extended Error code
 descriptions

On Thu, Jul 20, 2023 at 12:54:20PM +0000, Muralidhara M K wrote:
> From: Muralidhara M K <muralidhara.mk@....com>
> 
> On AMD systems with Scalable MCA, each machine check error of a SMCA bank
> type has an associated bit position in the bank's control (CTL) register.
> 
> An error's bit position in the CTL register is used during error decoding
> for offsetting into the corresponding bank's error description structure.
> As new errors are being added in newer AMD systems for existing SMCA bank
> types, the underlying SMCA architecture guarantees that the bit positions
> of existing errors are not altered.
> 
> However, on some AMD systems some of the existing bit definitions in the
> CTL register of SMCA bank type are reassigned without defining new HWID
> and McaType. Consequently, the errors whose bit definitions have been
> reassigned in the CTL register are being erroneously decoded.
> 
> Remove SMCA Extended Error Code descriptions. This avoids decoding issues
> for incorrectly reassigned bits, and avoids the related maintenance burden
> in the kernel. This decoding can be done in external tools or by referring
> to AMD documentation. The bank type and Extended Error Code value for an
> error will continue to be printed as a convenience.
> 
> Signed-off-by: Muralidhara M K <muralidhara.mk@....com>
> Reviewed-by: Yazen Ghannam <yazen.ghannam@....com>
> ---
>  drivers/edac/mce_amd.c | 480 -----------------------------------------
>  1 file changed, 480 deletions(-)

This needs to stay until rasdaemon has support for decoding errors - and
I've told you already.

Lemme tell you again, maybe it'll stick this time.

In any case, NAK.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette