From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Osipenko <digetx@gmail.com>
Date: Fri, 10 Dec 2021 19:44:41 +0000
Subject: Re: [PATCH v4 05/25] reboot: Warn if restart handler has duplicated priority
Message-Id: <ad6c7d73-e7d3-4901-fd63-ef87eecd39a2@gmail.com>
List-Id: <linux-ia64.vger.kernel.org>
References: <20211126180101.27818-1-digetx@gmail.com>
 <20211126180101.27818-6-digetx@gmail.com> <YaLNOJTM+lVq+YNS@qmqm.qmqm.pl>
 <033ddf2a-6223-1a82-ec64-30f17c891f67@gmail.com>
 <YaQeQgbW+CjEdsqG@qmqm.qmqm.pl>
 <091321ea-4919-0579-88a8-23d05871575d@gmail.com>
 <CAJZ5v0jMvdhfBqjY+V9h_Z6EH1ohuJH+KjuGiOw_Jor1Tnp7vg@mail.gmail.com>
 <45025b2d-4be1-f694-be61-31903795cf5d@gmail.com>
 <CAJZ5v0ieTwnBVjW8R_VTdPFH3yr5AwLc+ZEG5N3KrpTH+j8qZw@mail.gmail.com>
 <45228c88-4d51-591e-5da5-9ec468e71684@gmail.com>
In-Reply-To: <45228c88-4d51-591e-5da5-9ec468e71684@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <mirq-linux@rere.qmqm.pl>, 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>, Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Yoshinori Sato <ysato@users.sourceforge.jp>, Rich Felker <dalias@libc.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, the arch/x86 maintainers <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, Juergen Gross <jgross@suse.com>, Stefano Stabellini <sstabellini@kernel.org>, Len Brown <lenb@kernel.org>, Santosh Shilimkar <ssantosh@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>, Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>, Pavel Machek <pavel@ucw.cz>, Lee Jones <lee.jones@linaro.org>, Andrew Morton <akpm@linux-foundation.org>, Guenter Roeck <linux@roeck-us.net>, Daniel Lezcano <daniel.lezcano@linaro.org>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Ulf Hansson <ulf.hansson@linaro.org>, alankao@andestech.com, "K . C . Kuen-Chern Lin" <kclin@andestech.com>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-riscv@lists.infradead.org, Linux-sh list <linux-sh@vger.kernel.org>, xen-devel@lists.xenproject.org, ACPI Devel Maling List <linux-acpi@vger.kernel.org>, Linux PM <linux-pm@vger.kernel.org>, linux-tegra <linux-tegra@vger.kernel.org>

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.