linux-kernel - Re: [PATCH] iio: adc: ad_sigma_delta.c: Cleaning up uninitialized variables

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Message-ID: <CAFo99gaTK__WX4oTr_jF6PZuTOsX8qbR9kRJbgamZPO4iGz53w@mail.gmail.com>
Date:	Sun, 1 Jun 2014 13:51:54 +0200
From:	Rickard Strandqvist <rickard_strandqvist@...ctrumdigital.se>
To:	Lars-Peter Clausen <lars@...afoo.de>
Cc:	Jonathan Cameron <jic23@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Wolfram Sang <wsa@...-dreams.de>, linux-iio@...r.kernel.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] iio: adc: ad_sigma_delta.c: Cleaning up uninitialized variables

Hi

Believe it reacted to the code below.

If raw_sample = 0 is the correct starting value, I am not sure. But
leaving it uninitialized, I think is the worst choice.


    if (ret < 0)
        goto out;

    ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA,
        DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
        &raw_sample);
....
out:
....
    sample = raw_sample >> chan->scan_type.shift;


Best regards
Rickard Strandqvist


2014-06-01 11:15 GMT+02:00 Lars-Peter Clausen <lars@...afoo.de>:
> On 06/01/2014 01:11 AM, Rickard Strandqvist wrote:
>>
>> There is a risk that the variable will be used without being initialized.
>>
>> This was largely found by using a static code analysis program called
>> cppcheck.
>
>
> This looks like a false positive. And if it was not a false positive the
> correct fix certainly is not to initialize the variable to some random value
> to silence the warning.
>
> - Lars
>
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