linux-kernel - Re: [PATCH 1/1] thunderbolt: Deletion of unnecessary checks before the function call "ring

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Date:	Fri, 21 Nov 2014 12:29:03 +0100
From:	Andreas Noever <andreas.noever@...il.com>
To:	SF Markus Elfring <elfring@...rs.sourceforge.net>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	kernel-janitors@...r.kernel.org,
	Julia Lawall <julia.lawall@...6.fr>
Subject: Re: [PATCH 1/1] thunderbolt: Deletion of unnecessary checks before
 the function call "ring_free"

Hi Markus,

ring_free does not check for null:
http://lxr.free-electrons.com/source/drivers/thunderbolt/nhi.c#L398

Maybe your software confuses the method with:
http://lxr.free-electrons.com/source/drivers/char/tpm/xen-tpmfront.c#L268

Andreas

On Fri, Nov 21, 2014 at 11:40 AM, SF Markus Elfring
<elfring@...rs.sourceforge.net> wrote:
> From: Markus Elfring <elfring@...rs.sourceforge.net>
> Date: Fri, 21 Nov 2014 11:30:18 +0100
>
> The ring_free() function tests whether its argument is NULL and then
> returns immediately. Thus the test around the call is not needed.
>
> This issue was detected by using the Coccinelle software.
>
> Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
> ---
>  drivers/thunderbolt/ctl.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
> index 799634b..55b9bdf 100644
> --- a/drivers/thunderbolt/ctl.c
> +++ b/drivers/thunderbolt/ctl.c
> @@ -520,10 +520,8 @@ err:
>  void tb_ctl_free(struct tb_ctl *ctl)
>  {
>         int i;
> -       if (ctl->rx)
> -               ring_free(ctl->rx);
> -       if (ctl->tx)
> -               ring_free(ctl->tx);
> +       ring_free(ctl->rx);
> +       ring_free(ctl->tx);
>
>         /* free RX packets */
>         for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
> --
> 2.1.3
>
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