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Subject: Re: [PATCH] drm/msm/mdp5: 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, abhinavk@codeaurora.org
Cc:     linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20201231094935.25737-1-vulab@iscas.ac.cn>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Message-ID: <b8e7ca23-b8aa-18ef-c4a9-2fcaec0f52f6@linaro.org>
Date:   Sat, 2 Oct 2021 22:48:45 +0300
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On 31/12/2020 12:49, 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/mdp5/mdp5_kms.c  | 18 ++++++------------
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_mdss.c | 12 ++++--------
>   2 files changed, 10 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index 15aed45022bc..8d373d2ffd51 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -303,15 +303,12 @@ static int mdp5_disable(struct mdp5_kms *mdp5_kms)
>   	mdp5_kms->enable_count--;
>   	WARN_ON(mdp5_kms->enable_count < 0);
>   
> -	if (mdp5_kms->tbu_rt_clk)
> -		clk_disable_unprepare(mdp5_kms->tbu_rt_clk);
> -	if (mdp5_kms->tbu_clk)
> -		clk_disable_unprepare(mdp5_kms->tbu_clk);
> +	clk_disable_unprepare(mdp5_kms->tbu_rt_clk);
> +	clk_disable_unprepare(mdp5_kms->tbu_clk);
>   	clk_disable_unprepare(mdp5_kms->ahb_clk);
>   	clk_disable_unprepare(mdp5_kms->axi_clk);
>   	clk_disable_unprepare(mdp5_kms->core_clk);
> -	if (mdp5_kms->lut_clk)
> -		clk_disable_unprepare(mdp5_kms->lut_clk);
> +	clk_disable_unprepare(mdp5_kms->lut_clk);
>   
>   	return 0;
>   }
> @@ -325,12 +322,9 @@ static int mdp5_enable(struct mdp5_kms *mdp5_kms)
>   	clk_prepare_enable(mdp5_kms->ahb_clk);
>   	clk_prepare_enable(mdp5_kms->axi_clk);
>   	clk_prepare_enable(mdp5_kms->core_clk);
> -	if (mdp5_kms->lut_clk)
> -		clk_prepare_enable(mdp5_kms->lut_clk);
> -	if (mdp5_kms->tbu_clk)
> -		clk_prepare_enable(mdp5_kms->tbu_clk);
> -	if (mdp5_kms->tbu_rt_clk)
> -		clk_prepare_enable(mdp5_kms->tbu_rt_clk);
> +	clk_prepare_enable(mdp5_kms->lut_clk);
> +	clk_prepare_enable(mdp5_kms->tbu_clk);
> +	clk_prepare_enable(mdp5_kms->tbu_rt_clk);
>   
>   	return 0;
>   }
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mdss.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mdss.c
> index 09bd46ad820b..02c6c4b68c68 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mdss.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mdss.c
> @@ -137,10 +137,8 @@ static int mdp5_mdss_enable(struct msm_mdss *mdss)
>   	DBG("");
>   
>   	clk_prepare_enable(mdp5_mdss->ahb_clk);
> -	if (mdp5_mdss->axi_clk)
> -		clk_prepare_enable(mdp5_mdss->axi_clk);
> -	if (mdp5_mdss->vsync_clk)
> -		clk_prepare_enable(mdp5_mdss->vsync_clk);
> +	clk_prepare_enable(mdp5_mdss->axi_clk);
> +	clk_prepare_enable(mdp5_mdss->vsync_clk);
>   
>   	return 0;
>   }
> @@ -150,10 +148,8 @@ static int mdp5_mdss_disable(struct msm_mdss *mdss)
>   	struct mdp5_mdss *mdp5_mdss = to_mdp5_mdss(mdss);
>   	DBG("");
>   
> -	if (mdp5_mdss->vsync_clk)
> -		clk_disable_unprepare(mdp5_mdss->vsync_clk);
> -	if (mdp5_mdss->axi_clk)
> -		clk_disable_unprepare(mdp5_mdss->axi_clk);
> +	clk_disable_unprepare(mdp5_mdss->vsync_clk);
> +	clk_disable_unprepare(mdp5_mdss->axi_clk);
>   	clk_disable_unprepare(mdp5_mdss->ahb_clk);
>   
>   	return 0;
> 


-- 
With best wishes
Dmitry