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Re: [PATCH] mips: set ST0_MX flag for MDMX

To: "Maciej W. Rozycki" <macro@linux-mips.org>
Subject: Re: [PATCH] mips: set ST0_MX flag for MDMX
From: Matt Turner <mattst88@gmail.com>
Date: Wed, 9 May 2012 15:21:33 -0400
Cc: Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
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On Wed, May 9, 2012 at 1:20 PM, Maciej W. Rozycki <macro@linux-mips.org> wrote:
>> As the comment in commit 3301edcb says, DSP and MDMX share the same
>> config flag bit.
>>
>> Without this set, MDMX instructions cause Illegal instruction errors.
>
>  NAK, it's all pretty and nice, but I am afraid you're missing the point
> with your change.  The bit has its purpose, the MDMX accumulator has to be
> saved and restored -- just as the DSP or the FPU context -- between task
> switches and the bit provides for doing that lazily (of course you can do
> that eagerly instead if you like).

Okay. It looks like I also need to add save/restoring of the MDMX
accumulator to arch/mips/power/cpu.c and
arch/mips/include/asm/switch_to.h:finish_arch_switch()?

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