Re: [alsa-devel] [PATCH 1/3] ASoC: simple-card: Use devm_kcalloc() in asoc_simple_card_parse_aux_devs()

From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: SF Markus Elfring <elfring@users.sourceforge.net>
Cc: alsa-devel@alsa-project.org, Jaroslav Kysela <perex@perex.cz>,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	Nikita Yushchenko <nikita.yoush@cogentembedded.com>,
	Takashi Iwai <tiwai@suse.com>,
	kernel-janitors@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [alsa-devel] [PATCH 1/3] ASoC: simple-card: Use devm_kcalloc() in asoc_simple_card_parse_aux_devs()
Date: Fri, 28 Apr 2017 10:57:35 +0200	[thread overview]
Message-ID: <20170428085735.i7xpxph24t5v5f5q@piout.net> (raw)
In-Reply-To: <8c8c6979-0368-9ef5-2e10-57199f0bc03e@users.sourceforge.net>

Hi,

On 26/04/2017 at 15:04:11 +0200, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 26 Apr 2017 14:21:51 +0200
> 
> A multiplication for the size determination of a memory allocation
> indicated that an array data structure should be processed.
> Thus use the corresponding function "devm_kcalloc".
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  sound/soc/generic/simple-card.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
> index 2c9dedab5184..b59d51374b89 100644
> --- a/sound/soc/generic/simple-card.c
> +++ b/sound/soc/generic/simple-card.c
> @@ -334,8 +334,8 @@ static int asoc_simple_card_parse_aux_devs(struct device_node *node,
>  	if (n <= 0)
>  		return -EINVAL;
>  
> -	card->aux_dev = devm_kzalloc(dev,
> -			n * sizeof(*card->aux_dev), GFP_KERNEL);
> +	card->aux_dev = devm_kcalloc(dev, n, sizeof(*card->aux_dev),
> +				     GFP_KERNEL);

Do you realize that this change has absolutely no value and just makes
the code slower (one more test in the allocation path)?

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com