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From:   Stephen Zhang <starzhangzsd@gmail.com>
Date:   Sun, 1 May 2022 10:54:17 +0800
Message-ID: <CANubcdUxobBn968rtz0z-zZVJQfV5k3PQcdLdXNbsw3mEphk0A@mail.gmail.com>
Subject: Re: [PATCH v2] MIPS: undefine and redefine cpu_has_fpu when it is overrided
To:     "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        liam.howlett@oracle.com, ebiederm@xmission.com, alobakin@pm.me,
        f.fainelli@gmail.com, paul@crapouillou.net, linux@roeck-us.net,
        anemo@mba.ocn.ne.jp, 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=8830=E6=
=97=A5=E5=91=A8=E5=85=AD 23:38=E5=86=99=E9=81=93=EF=BC=9A
>
>  Adding a safety check would be a separate improvement.  Please feel free
> to submit one.
>
>  We need to keep fixes and improvements as separate changes.  For one
> fixes can be candidates for backporting while improvements are never
> backported; cf. Documentation/process/stable-kernel-rules.rst.
>
>  I hope this clears your concerns.  Let me know if you have further
> questions.
>
>   Maciej

Thanks for your elaboration.It helps a lot.
I want to submit a v3 patch like:

#if cpu_has_fpu
# error "Forcing `cpu_has_fpu' to non-zero is not supported"
#endif

but this will cause the link error if not combined with the fix:

MIPS: IP30: Remove incorrect `cpu_has_fpu' override

Maybe I should submit one first, and see how it goes then.