Re: [PATCH v7 2/4] drm/mediatek: Fix using wrong drm private data to bind mediatek-drm

[CK Hu (胡俊光)]

Hi, Jason:

On Fri, 2023-07-28 at 00:41 +0800, Jason-JH.Lin wrote:
> Add checking the length of each data path before assigning drm
> private
> data into all_drm_priv array.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> 
> Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195
> multi mmsys support")
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 249c9fd6347e..d2fb1fb4e682 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -351,6 +351,7 @@ static bool mtk_drm_get_all_drm_priv(struct
> device *dev)
>  {
>  	struct mtk_drm_private *drm_priv = dev_get_drvdata(dev);
>  	struct mtk_drm_private *all_drm_priv[MAX_CRTC];
> +	struct mtk_drm_private *temp_drm_priv;
>  	struct device_node *phandle = dev->parent->of_node;
>  	const struct of_device_id *of_id;
>  	struct device_node *node;
> @@ -373,9 +374,18 @@ static bool mtk_drm_get_all_drm_priv(struct
> device *dev)
>  		if (!drm_dev || !dev_get_drvdata(drm_dev))
>  			continue;
>  
> -		all_drm_priv[cnt] = dev_get_drvdata(drm_dev);
> -		if (all_drm_priv[cnt] && all_drm_priv[cnt]-
> >mtk_drm_bound)
> -			cnt++;
> +		temp_drm_priv = dev_get_drvdata(drm_dev);
> +		if (temp_drm_priv) {
> +			if (temp_drm_priv->mtk_drm_bound)
> +				cnt++;
> +
> +			if (temp_drm_priv->data->main_len)
> +				all_drm_priv[0] = temp_drm_priv;
> +			else if (temp_drm_priv->data->ext_len)
> +				all_drm_priv[1] = temp_drm_priv;
> +			else if (temp_drm_priv->data->third_len)
> +				all_drm_priv[2] = temp_drm_priv;
> +		}
>  	}
>  
>  	if (drm_priv->data->mmsys_dev_num == cnt) {