From: Duan Andy <fugang.duan@freescale.com>
To: =?utf-8?B?TG90aGFyIFdhw59tYW5u?= <LW@KARO-electronics.de>,
        Andrew Lunn <andrew@lunn.ch>, "David S. Miller" <davem@davemloft.net>,
        Fabio Estevam <Fabio.Estevam@freescale.com>,
        Greg Ungerer <gerg@uclinux.org>, Kevin Hao <haokexin@gmail.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        Philippe Reynes <tremyfr@gmail.com>,
        Richard Cochran <richardcochran@gmail.com>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        "Stefan Agner" <stefan@agner.ch>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
        "Uwe Kleine-K?nig" <u.kleine-koenig@pengutronix.de>
Subject: RE: [PATCH 1/3] net: fec: Remove redundant checks for NULL clk
 pointer
Thread-Topic: [PATCH 1/3] net: fec: Remove redundant checks for NULL clk
 pointer
Thread-Index: AQHRK2LolxcKij+aUEaoy3quCpVc4Z61YfzA
Date: Tue, 1 Dec 2015 02:04:39 +0000
Message-ID: <BN3PR0301MB1219B4C39D2D9202A5C96349F50F0@BN3PR0301MB1219.namprd03.prod.outlook.com>
References: <1448883168-30742-1-git-send-email-LW@KARO-electronics.de>
 <1448883168-30742-2-git-send-email-LW@KARO-electronics.de>
In-Reply-To: <1448883168-30742-2-git-send-email-LW@KARO-electronics.de>
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From: Lothar Waßmann <LW@KARO-electronics.de> Sent: Monday, November 30, 2015 7:33 PM
> To: Andrew Lunn; David S. Miller; Estevam Fabio-R49496; Greg Ungerer;
> Kevin Hao; Lothar Waßmann; Lucas Stach; Duan Fugang-B38611; Philippe
> Reynes; Richard Cochran; Russell King; Sascha Hauer; Stefan Agner; linux-
> kernel@vger.kernel.org; netdev@vger.kernel.org; Jeff Kirsher; Uwe Kleine-
> König
> Subject: [PATCH 1/3] net: fec: Remove redundant checks for NULL clk
> pointer
> 
> NULL is a valid argument to clk_enable()/clk_disable(). Remove redundant
> checks before calling those functions.
> 
> Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> ---
>  drivers/net/ethernet/freescale/fec_main.c | 23 +++++++++--------------
>  1 file changed, 9 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index d2328fc..e17d74f 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1873,35 +1873,30 @@ static int fec_enet_clk_enable(struct net_device
> *ndev, bool enable)
>  			}
>  			mutex_unlock(&fep->ptp_clk_mutex);
>  		}
> -		if (fep->clk_ref) {
> -			ret = clk_prepare_enable(fep->clk_ref);
> -			if (ret)
> -				goto failed_clk_ref;
> -		}
> +
> +		ret = clk_prepare_enable(fep->clk_ref);
> +		if (ret)
> +			goto failed_clk_ref;

If you want to clean up the code, pls also remove "fep->clk_enet_out" check in this brace.


>  	} else {
>  		clk_disable_unprepare(fep->clk_ahb);
> -		if (fep->clk_enet_out)
> -			clk_disable_unprepare(fep->clk_enet_out);
> +		clk_disable_unprepare(fep->clk_enet_out);
>  		if (fep->clk_ptp) {
>  			mutex_lock(&fep->ptp_clk_mutex);
>  			clk_disable_unprepare(fep->clk_ptp);
>  			fep->ptp_clk_on = false;
>  			mutex_unlock(&fep->ptp_clk_mutex);
>  		}
> -		if (fep->clk_ref)
> -			clk_disable_unprepare(fep->clk_ref);
> +		clk_disable_unprepare(fep->clk_ref);
>  	}
> 
>  	return 0;
> 
>  failed_clk_ref:
> -	if (fep->clk_ref)
> -		clk_disable_unprepare(fep->clk_ref);
> +	clk_disable_unprepare(fep->clk_ref);
>  failed_clk_ptp:
> -	if (fep->clk_enet_out)
> -		clk_disable_unprepare(fep->clk_enet_out);
> +	clk_disable_unprepare(fep->clk_enet_out);
>  failed_clk_enet_out:
> -		clk_disable_unprepare(fep->clk_ahb);
> +	clk_disable_unprepare(fep->clk_ahb);
> 
>  	return ret;
>  }
> --
> 2.1.4
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