linux-kernel - Re: [PATCH 16/28] pcmcia: fix return value of soc_pcmcia_regulator

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Message-ID: <20161018094159.GK1041@n2100.armlinux.org.uk>
Date:   Tue, 18 Oct 2016 10:42:00 +0100
From:   Russell King - ARM Linux <linux@...linux.org.uk>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, linux-pcmcia@...ts.infradead.org
Subject: Re: [PATCH 16/28] pcmcia: fix return value of
 soc_pcmcia_regulator_set

On Tue, Oct 18, 2016 at 12:13:37AM +0200, Arnd Bergmann wrote:
> The newly introduced soc_pcmcia_regulator_set() function sometimes returns
> without setting its return code, as shown by this warning:
> 
> drivers/pcmcia/soc_common.c: In function 'soc_pcmcia_regulator_set':
> drivers/pcmcia/soc_common.c:112:5: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> This changes it to propagate the regulator_disable() result instead.

I guess this is the problem with the stupid patch which silences this
warning - I don't see this warning here.

Having this warning disabled means that _real_ coding errors end up
making their way into the kernel (yes, this should be an error, this
is not a warning, because the value of 'ret' is completely undefined,
and therefore the behaviour of the following code is undefined.)

With the warning silenced, it means that such errors are undetectable.
I knew nothing about this until I received this patch, and I always
check that the code I send is warning-free on the GCC I'm using.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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