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Date: Thu, 17 Sep 2015 10:57:59 +0200 (CEST)
From: Julia Lawall <julia.lawall@lip6.fr>
X-X-Sender: jll@hadrien
To: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
cc: kbuild-all@01.org, Felipe Balbi <balbi@ti.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: gadget: uvc: fix returnvar.cocci warnings
In-Reply-To: <20150917000130.GA25134@lkp-ib04>
Message-ID: <alpine.DEB.2.10.1509171056470.2399@hadrien>
References: <201509170828.xv0cYNA5%fengguang.wu@intel.com> <20150917000130.GA25134@lkp-ib04>
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Coccinelle suggests the following patch.  But the code is curious.  Is the
function expected to always return a failure value?

thanks,
julia

On Thu, 17 Sep 2015, kbuild test robot wrote:

> TO: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
> CC: kbuild-all@01.org
> CC: Felipe Balbi <balbi@ti.com>
> CC: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
> CC: linux-usb@vger.kernel.org
> CC: linux-kernel@vger.kernel.org
>
> drivers/usb/gadget/function/uvc_configfs.c:866:5-8: Unneeded variable: "ret". Return "- EINVAL" on line 891
>
>
>  Remove unneeded variable used to store return value.
>
> Generated by: scripts/coccinelle/misc/returnvar.cocci
>
> CC: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
> ---
>
> Please take the patch only if it's a positive warning. Thanks!
>
>  uvc_configfs.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> --- a/drivers/usb/gadget/function/uvc_configfs.c
> +++ b/drivers/usb/gadget/function/uvc_configfs.c
> @@ -863,7 +863,6 @@ static int uvcg_streaming_header_drop_li
>  	struct uvcg_streaming_header *src_hdr;
>  	struct uvcg_format *target_fmt = NULL;
>  	struct uvcg_format_ptr *format_ptr, *tmp;
> -	int ret = -EINVAL;
>
>  	src_hdr = to_uvcg_streaming_header(src);
>  	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
> @@ -888,7 +887,7 @@ static int uvcg_streaming_header_drop_li
>  out:
>  	mutex_unlock(&opts->lock);
>  	mutex_unlock(su_mutex);
> -	return ret;
> +	return -EINVAL;
>
>  }
>
>