From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gang.chen@asianux.com>
Received: from intranet.asianux.com (intranet.asianux.com [58.214.24.6])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by ozlabs.org (Postfix) with ESMTPS id 693312C02C9
 for <linuxppc-dev@lists.ozlabs.org>; Mon, 27 May 2013 20:02:07 +1000 (EST)
Message-ID: <51A32EE9.1030704@asianux.com>
Date: Mon, 27 May 2013 18:01:13 +0800
From: Chen Gang <gang.chen@asianux.com>
MIME-Version: 1.0
To: Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH v2] PowerPC: kernel: need return the related error code
 when failure occurs
References: <519B0ACA.6090008@asianux.com>
 <20130521081031.GA29303@iris.ozlabs.ibm.com> <519B3855.6050201@asianux.com>
 <519B3C72.9060405@asianux.com>
In-Reply-To: <519B3C72.9060405@asianux.com>
Content-Type: text/plain; charset=UTF-8
Cc: Linux-Arch <linux-arch@vger.kernel.org>, Arnd Bergmann <arnd@arndb.de>,
 "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
 zhangyanfei@cn.fujitsu.com, Jiri Kosina <jkosina@suse.cz>,
 "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev/>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

Hello Maintainers:

Please help check this patch whether is OK, when you have time.

Thanks.

On 05/21/2013 05:20 PM, Chen Gang wrote:
> 
> When error occurs, need return the related error code to let upper
> caller know about it.
> 
> ppc_md.nvram_size() can return the error code (e.g. core99_nvram_size()
> in 'arch/powerpc/platforms/powermac/nvram.c').
> 
> Also set ret value when only need it, so can save structions for normal
> cases.
> 
> The original related patch: "f9ce299 [PATCH] powerpc: fix large nvram
> access".
> 
> 
> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> ---
>  arch/powerpc/kernel/nvram_64.c |   20 ++++++++++++++------
>  1 files changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
> index 48fbc2b..8213ee1 100644
> --- a/arch/powerpc/kernel/nvram_64.c
> +++ b/arch/powerpc/kernel/nvram_64.c
> @@ -84,22 +84,30 @@ static ssize_t dev_nvram_read(struct file *file, char __user *buf,
>  	char *tmp = NULL;
>  	ssize_t size;
>  
> -	ret = -ENODEV;
> -	if (!ppc_md.nvram_size)
> +	if (!ppc_md.nvram_size) {
> +		ret = -ENODEV;
>  		goto out;
> +	}
>  
> -	ret = 0;
>  	size = ppc_md.nvram_size();
> -	if (*ppos >= size || size < 0)
> +	if (size < 0) {
> +		ret = size;
> +		goto out;
> +	}
> +
> +	if (*ppos >= size) {
> +		ret = 0;
>  		goto out;
> +	}
>  
>  	count = min_t(size_t, count, size - *ppos);
>  	count = min(count, PAGE_SIZE);
>  
> -	ret = -ENOMEM;
>  	tmp = kmalloc(count, GFP_KERNEL);
> -	if (!tmp)
> +	if (!tmp) {
> +		ret = -ENOMEM;
>  		goto out;
> +	}
>  
>  	ret = ppc_md.nvram_read(tmp, count, ppos);
>  	if (ret <= 0)
> 


-- 
Chen Gang

Asianux Corporation