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Subject: Re: [PATCH] drm/msm/mdp4: Remove redundant null check before
 clk_prepare_enable/clk_disable_unprepare
To:     Xu Wang <vulab@iscas.ac.cn>, robdclark@gmail.com, sean@poorly.run,
        airlied@linux.ie, daniel@ffwll.ch, jcrouse@codeaurora.org,
        tzimmermann@suse.de, sam@ravnborg.org
Cc:     linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20201231094155.25481-1-vulab@iscas.ac.cn>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Message-ID: <3809d7e9-3aa6-8ac0-c1ea-88b63a3d6d63@linaro.org>
Date:   Sat, 2 Oct 2021 22:48:31 +0300
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On 31/12/2020 12:41, Xu Wang wrote:
> Because clk_prepare_enable() and clk_disable_unprepare() already checked
> NULL clock parameter, so the additional checks are unnecessary, just
> remove them.
> 
> Signed-off-by: Xu Wang <vulab@iscas.ac.cn>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 18 ++++++------------
>   1 file changed, 6 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> index 3d729270bde1..696a22d571ad 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> @@ -207,12 +207,9 @@ int mdp4_disable(struct mdp4_kms *mdp4_kms)
>   	DBG("");
>   
>   	clk_disable_unprepare(mdp4_kms->clk);
> -	if (mdp4_kms->pclk)
> -		clk_disable_unprepare(mdp4_kms->pclk);
> -	if (mdp4_kms->lut_clk)
> -		clk_disable_unprepare(mdp4_kms->lut_clk);
> -	if (mdp4_kms->axi_clk)
> -		clk_disable_unprepare(mdp4_kms->axi_clk);
> +	clk_disable_unprepare(mdp4_kms->pclk);
> +	clk_disable_unprepare(mdp4_kms->lut_clk);
> +	clk_disable_unprepare(mdp4_kms->axi_clk);
>   
>   	return 0;
>   }
> @@ -222,12 +219,9 @@ int mdp4_enable(struct mdp4_kms *mdp4_kms)
>   	DBG("");
>   
>   	clk_prepare_enable(mdp4_kms->clk);
> -	if (mdp4_kms->pclk)
> -		clk_prepare_enable(mdp4_kms->pclk);
> -	if (mdp4_kms->lut_clk)
> -		clk_prepare_enable(mdp4_kms->lut_clk);
> -	if (mdp4_kms->axi_clk)
> -		clk_prepare_enable(mdp4_kms->axi_clk);
> +	clk_prepare_enable(mdp4_kms->pclk);
> +	clk_prepare_enable(mdp4_kms->lut_clk);
> +	clk_prepare_enable(mdp4_kms->axi_clk);
>   
>   	return 0;
>   }
> 


-- 
With best wishes
Dmitry