Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 10 Apr 2019 18:40:36 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     "Ghannam, Yazen" <Yazen.Ghannam@amd.com>
Cc:     "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tony.luck@intel.com" <tony.luck@intel.com>,
        "x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH RESEND 2/5] x86/MCE: Handle MCA controls in a per_cpu way
Message-ID: <20190410164036.GC26580@zn.tnic>
References: <20190408141205.12376-1-Yazen.Ghannam@amd.com>
 <20190408141205.12376-3-Yazen.Ghannam@amd.com>
 <20190408175142.GK15689@zn.tnic>
 <SN6PR12MB26397E000684890C92075985F82C0@SN6PR12MB2639.namprd12.prod.outlook.com>
 <20190409203412.GE6150@zn.tnic>
 <SN6PR12MB2639C9B48E46DA6A8BA9DB3DF82E0@SN6PR12MB2639.namprd12.prod.outlook.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <SN6PR12MB2639C9B48E46DA6A8BA9DB3DF82E0@SN6PR12MB2639.namprd12.prod.outlook.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Apr 10, 2019 at 04:36:30PM +0000, Ghannam, Yazen wrote:
> We have this case on AMD Family 17h with Bank 4. The hardware enforces
> this bank to be Read-as-Zero/Writes-Ignored.
>
> This behavior is enforced whether the bank is in the middle or at the
> end.

Does num_banks contain the disabled bank? If so, then it will work.

> I'm thinking to redo the sysfs interface for banks in another patch
> set. I could include a new file to indicate enabled/disabled, or maybe
> just update the documentation to describe this case.

No, the write to the bank controls should fail on a disabled bank.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.