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Date:   Fri, 28 Aug 2020 13:12:57 +0200
From:   Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To:     Huacai Chen <chenhc@lemote.com>
Cc:     Jiaxun Yang <jiaxun.yang@flygoat.com>,
        "open list:MIPS" <linux-mips@vger.kernel.org>,
        Fuxin Zhang <zhangfx@lemote.com>,
        Zhangjin Wu <wuzhangjin@gmail.com>
Subject: Re: [PATCH V3 1/2] MIPS: Loongson-3: Enable COP2 usage in kernel
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On Fri, Aug 28, 2020 at 05:52:05PM +0800, Huacai Chen wrote:
> Hi, Thomas,
> 
> On Fri, Aug 28, 2020 at 5:34 PM Thomas Bogendoerfer
> <tsbogend@alpha.franken.de> wrote:
> > if it is enabled at that point, it was already enabled in kernel.
> In kernel FPU may be enabled temporarily, and it seems a preemptible
> kernel may enable FPU for a new process (maybe I'm wrong, this is a
> bit complex).

no you are completly right. We need to clear CU1 in this place otherwise
a orphan cpu warning will trigger. It's enabled, if the current thread owns
it, but the newly created thread doesn't.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]