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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Arnd Bergmann <arnd@arndb.de>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michal Simek <michal.simek@xilinx.com>,
        "linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH v2 09/11] powerpc/platforms: Move files from 4xx to 44x
In-Reply-To: <74e76b4e-5e4f-f3de-96a8-f6a451b3243a@c-s.fr>
References: <698e9a42a06eb856eef4501c3c0a182c034a5d8c.1585640941.git.christophe.leroy@c-s.fr> <50d0ce1a96fa978cd0dfabde30cf75d23691622a.1585640942.git.christophe.leroy@c-s.fr> <CAK8P3a3u4y7Zm8w43QScqUk6macBL1wO3S0qPisf9+d9FqSHfw@mail.gmail.com> <833d63fe-3b94-a3be-1abb-a629386aa0dd@c-s.fr> <CAK8P3a244P38c+JCRnf1EscQOSzaQQNZc6b5F=LFE2a_im8AqQ@mail.gmail.com> <74e76b4e-5e4f-f3de-96a8-f6a451b3243a@c-s.fr>
Date:   Wed, 01 Apr 2020 13:20:21 +1100
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Christophe Leroy <christophe.leroy@c-s.fr> writes:
> Le 31/03/2020 =C3=A0 18:04, Arnd Bergmann a =C3=A9crit=C2=A0:
>> On Tue, Mar 31, 2020 at 5:26 PM Christophe Leroy
>> <christophe.leroy@c-s.fr> wrote:
>>> Le 31/03/2020 =C3=A0 17:14, Arnd Bergmann a =C3=A9crit :
>>>> On Tue, Mar 31, 2020 at 9:49 AM Christophe Leroy
>>>> <christophe.leroy@c-s.fr> wrote:
>>>>>
>>>>> Only 44x uses 4xx now, so only keep one directory.
>>>>>
>>>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>>>> ---
>>>>>    arch/powerpc/platforms/44x/Makefile           |  9 +++++++-
>>>>>    arch/powerpc/platforms/{4xx =3D> 44x}/cpm.c     |  0
>>>>
>>>> No objections to moving everything into one place, but I wonder if the
>>>> combined name should be 4xx instead of 44x, given that 44x currently
>>>> include 46x and 47x. OTOH your approach has the advantage of
>>>> moving fewer files.
>>>>
>>>
>>> In that case, should we also rename CONFIG_44x to CONFIG_4xx ?
>>=20
>> That has the risk of breaking user's defconfig files, but given the
>> small number of users, it may be nicer for consistency. In either
>> case, the two symbols should probably hang around as synonyms,
>> the question is just which one is user visible.
>>=20
>
> Not sure it is a good idea to keep two synonyms. In the past we made our=
=20
> best to remove synonyms (We had CONFIG_8xx and CONFIG_PPC_8xx being=20
> synonyms, we had CONFIG_6xx and CONFIG_BOOK3S_32 and=20
> CONFIG_PPC_STD_MMU_32 being synonyms).
> I think it is a lot cleaner when we can avoid synonyms.
>
> By the way I already dropped CONFIG_4xx in previous patch (8/11). It was=
=20
> not many 4xx changed to 44x. It would be a lot more in the other way=20
> round I'm afraid.
>
> But I agree with you it might be more natural to change to 4xx.
>
> Michael, any preference ?

I'd say just use 44x, we've had the inconsistency of 476 living in
platforms/44x, and it hasn't really led to much confusion.

I think for most folks they see 4xx/44x and just think "some 32-bit
embedded thing", so the precise distinction between 4xx, 44x, 476 etc.
is not that important to justify renaming the symbol everywhere I think.

cheers