Re: [PATCH 0/2] powerpc: Remove support for ppc405/440 Xilinx platforms

From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Arnd Bergmann <arnd@arndb.de>
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	Thiago Jung Bauermann <bauerman@linux.ibm.com>
Subject: Re: [PATCH 0/2] powerpc: Remove support for ppc405/440 Xilinx platforms
Date: Tue, 31 Mar 2020 08:56:23 +0200	[thread overview]
Message-ID: <11765c82-bf1a-466c-760d-f9a4c4d1d5f1@c-s.fr> (raw)
In-Reply-To: <87mu7xum41.fsf@mpe.ellerman.id.au>

Le 31/03/2020 à 07:30, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>> Le 27/03/2020 à 15:14, Andy Shevchenko a écrit :
>>> On Fri, Mar 27, 2020 at 02:22:55PM +0100, Arnd Bergmann wrote:
>>>> On Fri, Mar 27, 2020 at 2:15 PM Andy Shevchenko
>>>> <andriy.shevchenko@linux.intel.com> wrote:
>>>>> On Fri, Mar 27, 2020 at 03:10:26PM +0200, Andy Shevchenko wrote:
>>>>>> On Fri, Mar 27, 2020 at 01:54:33PM +0100, Arnd Bergmann wrote:
>>>>>>> On Fri, Mar 27, 2020 at 1:12 PM Michal Simek <michal.simek@xilinx.com> wrote:
>>> ...
>>>
>>>>>>> It does raise a follow-up question about ppc40x though: is it time to
>>>>>>> retire all of it?
>>>>>>
>>>>>> Who knows?
>>>>>>
>>>>>> I have in possession nice WD My Book Live, based on this architecture, and I
>>>>>> won't it gone from modern kernel support. OTOH I understand that amount of real
>>>>>> users not too big.
>>>>>
>>>>> +Cc: Christian Lamparter, whom I owe for that WD box.
>>>>
>>>> According to https://openwrt.org/toh/wd/mybooklive, that one is based on
>>>> APM82181/ppc464, so it is about several generations newer than what I
>>>> asked about (ppc40x).
>>>>
>>>>>> Ah, and I have Amiga board, but that one is being used only for testing, so,
>>>>>> I don't care much.
>>>>
>>>> I think there are a couple of ppc440 based Amiga boards, but again, not 405
>>>> to my knowledge.
>>>
>>> Ah, you are right. No objections from ppc40x removal!
>>
>> Removing 40x would help cleaning things a bit. For instance 40x is the
>> last platform still having PTE_ATOMIC_UPDATES. So if we can remove 40x
>> we can get rid of PTE_ATOMIC_UPDATES completely.
>>
>> If no one objects, I can prepare a series to drop support for 40x
>> completely.
>>
>> Michael, any thought ?
> 
> I have no attachment to 40x, and I'd certainly be happy to have less
> code in the tree, we struggle to keep even the modern platforms well
> maintained.
> 
> At the same time I don't want to render anyone's hardware obsolete
> unnecessarily. But if there's really no one using 40x then we should
> remove it, it could well be broken already.
> 
> So I guess post a series to do the removal and we'll see if anyone
> speaks up.
> 

Ok, series sent out, see 
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=167757

While we are at it, can we also remove the 601 ? This one is also full 
of workarounds and diverges a bit from other 6xx.

I'm unable to find its end of life date, but it was on the market in 
1994, so I guess it must be outdated by more than 10-15 yr old now ?

Christophe