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From: Arnd Bergmann <arnd@arndb.de>
To: Ludovic BARRE <ludovic.barre@st.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
	Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
	Marek Vasut <marek.vasut@gmail.com>,
	Boris Brezillon <boris.brezillon@free-electrons.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	Richard Weinberger <richard@nod.at>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	MTD Maling List <linux-mtd@lists.infradead.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] mtd: spi-nor: stm32-quadspi: avoid unintialized return code
Date: Thu, 14 Sep 2017 23:38:19 +0200	[thread overview]
Message-ID: <CAK8P3a3WoUdxpaXAiMsC3MTWSyxyUK793R+igaQjTxdO7t+a6g@mail.gmail.com> (raw)
In-Reply-To: <f372a1cb-e255-b5de-510d-77ca944903b3@st.com>

On Thu, Sep 14, 2017 at 6:55 PM, Ludovic BARRE <ludovic.barre@st.com> wrote:
>
>
> On 09/14/2017 05:24 PM, Geert Uytterhoeven wrote:
>>
>> Hi Ludovic,
>>
>> On Thu, Sep 14, 2017 at 5:13 PM, Ludovic BARRE <ludovic.barre@st.com>
>> wrote:
>>>
>>> On 09/14/2017 03:38 PM, Geert Uytterhoeven wrote:
>>>
>>> hi Arnd, Geert
>>>
>>> sorry, I was forgot this thread while my holidays
>>>
>>> Geert: what do you mean like "similar bugs in the future" in "If you
>>> initialized ret at the beginning, you lose the ability to catch newly
>>> introduced similar bugs in the future."
>>
>>
>> If you pre-initialize ret at the top, you loose the ability of the
>> compiler
>> to detect at compile-time if ret is never written to later. It will just
>> return
>> -EINVAL at runtime.
>>
>> With my version, if the code is modified later and another "return ret" is
>> added, the compiler will detect if there's a code path that forgets
>> to assign a value to ret.
>
> Ok, it's clear for me.
> I favor geert's solution.
> Arnd what do you think ?

I usually follow the same rule that Geert explained (and quote
https://rusty.ozlabs.org/?p=232 when I do so). In this case, there
did not seem to be much value as the variable is not used
afterwards, and I kept the 'single return statement' guideline.

In the end, either version seems totally fine to me here, so
please use Geert's if you prefer that.

        Arnd

  reply	other threads:[~2017-09-14 21:38 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-14 11:06 [PATCH] mtd: spi-nor: stm32-quadspi: avoid unintialized return code Arnd Bergmann
2017-09-14 12:38 ` Ludovic BARRE
2017-09-14 13:38 ` Geert Uytterhoeven
2017-09-14 15:13   ` Ludovic BARRE
2017-09-14 15:24     ` Geert Uytterhoeven
2017-09-14 16:55       ` Ludovic BARRE
2017-09-14 21:38         ` Arnd Bergmann [this message]
2017-09-15  7:59           ` Ludovic BARRE

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