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In-Reply-To: <alpine.DEB.2.21.2204280951510.9383@angie.orcam.me.uk>
From:   Stephen Zhang <starzhangzsd@gmail.com>
Date:   Fri, 29 Apr 2022 11:10:25 +0800
Message-ID: <CANubcdXSHpV8xOBidXksMt+kLQ=jgNer4uisKbV5z9zxHp8dMw@mail.gmail.com>
Subject: Re: [PATCH] arch/mips/kernel/traps: add CONFIG_MIPS_FP_SUPPORT when
 using handle_fpe
To:     "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Joshua Kinard <kumba@gentoo.org>, liam.howlett@oracle.com,
        ebiederm@xmission.com, dbueso@suse.de, alobakin@pm.me,
        f.fainelli@gmail.com, zhangshida <zhangshida@kylinos.cn>,
        linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org
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Maciej W. Rozycki <macro@orcam.me.uk> =E4=BA=8E2022=E5=B9=B44=E6=9C=8828=E6=
=97=A5=E5=91=A8=E5=9B=9B 17:00=E5=86=99=E9=81=93=EF=BC=9A
>
> On Thu, 28 Apr 2022, Stephen Zhang wrote:
>  Thanks.
>
>  The bug is in arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h,
> which has:
>
> #define cpu_has_fpu                     1
>
> (and similarly arch/mips/include/asm/mach-ip30/cpu-feature-overrides.h).
> This is not supported, as noted in arch/mips/include/asm/cpu-features.h:
>
> /* Don't override `cpu_has_fpu' to 1 or the "nofpu" option won't work.  *=
/
>
> Perhaps we should explicitly undefine `cpu_has_fpu' if set to 1?
>
>   Maciej

Thanks for your detailed explanation and suggestion. I will make a v2 patch=
.