Date: Sat, 22 Oct 2016 20:51:08 -0500
From: Reza Arbab <arbab@linux.vnet.ibm.com>
To: Alistair Popple <apopple@au1.ibm.com>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Stewart Smith <stewart@linux.vnet.ibm.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Tang Chen <tangchen@cn.fujitsu.com>,
        linux-mm@kvack.org,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
        Bharata B Rao <bharata@linux.vnet.ibm.com>,
        Nathan Fontenot <nfont@linux.vnet.ibm.com>
Subject: Re: [PATCH v4 2/5] drivers/of: do not add memory for unavailable
 nodes
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Hi Alistair,

On Fri, Oct 21, 2016 at 05:22:54PM +1100, Alistair Popple wrote:
>From what I can tell it seems that kernels without this patch will try 
>and use this memory even if it is marked in the device-tree as 
>status="disabled" which could lead to problems for older kernels when 
>we start exporting this property from firmware.
>
>Arguably this might not be such a problem in practice as we probably 
>don't have many (if any) existing kernels that will boot on hardware 
>exporting these properties.

Yes, I think you've got it right.

>However given this patch seems fairly independent perhaps it is worth 
>sending as a separate fix if it is not going to make it into this 
>release?

Michael,

If this set as a whole is going to miss the release, would it be helpful 
for me to resend 1/5 and 2/5 as a separate set? They are the minimum 
needed to prevent the possible forward compatibility issue Alistair 
describes.

-- 
Reza Arbab