netdev - RE: [PATCH] net: fec: drop check for clk==NULL before calling clk

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Date:   Thu, 20 Oct 2016 08:56:40 +0000
From:   Andy Duan <fugang.duan@....com>
To:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
CC:     "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: RE: [PATCH] net: fec: drop check for clk==NULL before calling clk_*

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de> Sent: Thursday, October 20, 2016 4:28 PM
> To: Andy Duan <fugang.duan@....com>
> Cc: kernel@...gutronix.de; netdev@...r.kernel.org
> Subject: [PATCH] net: fec: drop check for clk==NULL before calling clk_*
> 
> clk_prepare, clk_enable and their counterparts (at least the common clk
> ones, but also most others) do check for the clk being NULL anyhow (and
> return 0 then), so there is no gain when the caller checks, too.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
> ---

Acked-by: Fugang Duan <fugang.duan@....com>

>  drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 48a033e64423..1722ccac18c2 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1841,11 +1841,11 @@ static int fec_enet_clk_enable(struct net_device
> *ndev, bool enable)
>  		ret = clk_prepare_enable(fep->clk_ahb);
>  		if (ret)
>  			return ret;
> -		if (fep->clk_enet_out) {
> -			ret = clk_prepare_enable(fep->clk_enet_out);
> -			if (ret)
> -				goto failed_clk_enet_out;
> -		}
> +
> +		ret = clk_prepare_enable(fep->clk_enet_out);
> +		if (ret)
> +			goto failed_clk_enet_out;
> +
>  		if (fep->clk_ptp) {
>  			mutex_lock(&fep->ptp_clk_mutex);
>  			ret = clk_prepare_enable(fep->clk_ptp); @@ -
> 1857,23 +1857,20 @@ 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;
>  	} 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;
> --
> 2.9.3