Subject: Re: [PATCH v4 05/25] reboot: Warn if restart handler has duplicated
 priority
From:   Dmitry Osipenko <digetx@gmail.com>
To:     "Rafael J. Wysocki" <rafael@kernel.org>,
        =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <mirq-linux@rere.qmqm.pl>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Russell King <linux@armlinux.org.uk>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Greg Ungerer <gerg@linux-m68k.org>,
        Joshua Thompson <funaho@jurai.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Sebastian Reichel <sre@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Greentime Hu <green.hu@gmail.com>,
        Vincent Chen <deanbo422@gmail.com>,
        "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
        Helge Deller <deller@gmx.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
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        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
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        Thomas Gleixner <tglx@linutronix.de>,
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Message-ID: <7875d10b-0d9b-ca29-668b-630ea3650fd0@gmail.com>
Date:   Fri, 10 Dec 2021 22:49:47 +0300
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10.12.2021 22:44, Dmitry Osipenko пишет:
> 10.12.2021 22:42, Dmitry Osipenko пишет:
> ...
>>>> There is no strong requirement for priorities to be unique, the reboot.c
>>>> code will work properly.
>>>
>>> In which case adding the WARN() is not appropriate IMV.
>>>
>>> Also I've looked at the existing code and at least in some cases the
>>> order in which the notifiers run doesn't matter.  I'm not sure what
>>> the purpose of this patch is TBH.
>>
>> The purpose is to let developer know that driver needs to be corrected.
>>
>>>> The potential problem is on the user's side and the warning is intended
>>>> to aid the user.
>>>
>>> Unless somebody has the panic_on_warn mentioned previously set and
>>> really the user need not understand what the WARN() is about.  IOW,
>>> WARN() helps developers, not users.
>>>
>>>> We can make it a strong requirement, but only after converting and
>>>> testing all kernel drivers.
>>>
>>> Right.
>>>
>>>> I'll consider to add patches for that.
>>>
>>> But can you avoid adding more patches to this series?
>>
>> I won't add more patches since such patches can be added only after
>> completion of transition to the new API of the whole kernel.
>>
> 
> Thank you for the review.
> 

I meant you, Rafael, and Michał, just in case :)