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Message-ID: <339d9ec4-a554-d468-51f4-498d785685b6@quicinc.com>
Date:   Tue, 6 Dec 2022 08:32:14 -0800
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Subject: Re: [PATCH] drm/msm/dpu: Add check for cstate
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To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, <robdclark@gmail.com>,
        <dmitry.baryshkov@linaro.org>, <sean@poorly.run>,
        <airlied@gmail.com>, <daniel@ffwll.ch>,
        <quic_jesszhan@quicinc.com>, <ville.syrjala@linux.intel.com>,
        <yang.lee@linux.alibaba.com>
CC:     <linux-arm-msm@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
        <freedreno@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>
References: <20221206080517.43786-1-jiasheng@iscas.ac.cn>
From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <20221206080517.43786-1-jiasheng@iscas.ac.cn>
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On 12/6/2022 12:05 AM, Jiasheng Jiang wrote:
> As kzalloc may fail and return NULL pointer,
> it should be better to check cstate
> in order to avoid the NULL pointer dereference
> in __drm_atomic_helper_crtc_reset.

You have wrapped around your lines too short. Please try to utilize the 
full word limit for each line.

With that fixed,

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

> 
> Fixes: 1cff7440a86e ("drm/msm: Convert to using __drm_atomic_helper_crtc_reset() for reset.")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 13ce321283ff..22c2787b7b38 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -968,7 +968,10 @@ static void dpu_crtc_reset(struct drm_crtc *crtc)
>   	if (crtc->state)
>   		dpu_crtc_destroy_state(crtc, crtc->state);
>   
> -	__drm_atomic_helper_crtc_reset(crtc, &cstate->base);
> +	if (cstate)
> +		__drm_atomic_helper_crtc_reset(crtc, &cstate->base);
> +	else
> +		__drm_atomic_helper_crtc_reset(crtc, NULL);
>   }
>   
>   /**