[PATCH v3 10/24] scsi: ufs: mediatek: Rework probe function

[Chaotian Jing (井朝天)]

On Thu, 2025-10-23 at 21:49 +0200, Nicolas Frattaroli wrote:
> Remove the ti,syscon-reset cruft.
> 
> Make PHY mandatory. All the compatibles supported by the binding make
> it
> mandatory.
> 
why make the PHY mandatory ? note that not all of MediaTek SoCs have
the PHY node.
> Entertain this driver's insistence on playing with the PHY's RPM, but
> at
> least fix the part where it doesn't increase the reference count,
> which
> would lead to use-after-free.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli at collabora.com>
> ---
>  drivers/ufs/host/ufs-mediatek.c | 87 +++++++++++++++--------------
> ------------
>  1 file changed, 32 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-
> mediatek.c
> index 9c0ac72d6e43..889a1d58a041 100644
> --- a/drivers/ufs/host/ufs-mediatek.c
> +++ b/drivers/ufs/host/ufs-mediatek.c
> @@ -2353,74 +2353,49 @@ MODULE_DEVICE_TABLE(of, ufs_mtk_of_match);
>   */
>  static int ufs_mtk_probe(struct platform_device *pdev)
>  {
> -	int err;
> -	struct device *dev = &pdev->dev, *phy_dev = NULL;
> -	struct device_node *reset_node, *phy_node = NULL;
> -	struct platform_device *reset_pdev, *phy_pdev = NULL;
> -	struct device_link *link;
> -	struct ufs_hba *hba;
> +	struct platform_device *phy_pdev;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *phy_node;
>  	struct ufs_mtk_host *host;
> +	struct device *phy_dev;
> +	struct ufs_hba *hba;
> +	int err;
>  
> -	reset_node = of_find_compatible_node(NULL, NULL,
> -					     "ti,syscon-reset");
> -	if (!reset_node) {
> -		dev_notice(dev, "find ti,syscon-reset fail\n");
> -		goto skip_reset;
> -	}
> -	reset_pdev = of_find_device_by_node(reset_node);
> -	if (!reset_pdev) {
> -		dev_notice(dev, "find reset_pdev fail\n");
> -		goto skip_reset;
> -	}
> -	link = device_link_add(dev, &reset_pdev->dev,
> -		DL_FLAG_AUTOPROBE_CONSUMER);
> -	put_device(&reset_pdev->dev);
> -	if (!link) {
> -		dev_notice(dev, "add reset device_link fail\n");
> -		goto skip_reset;
> -	}
> -	/* supplier is not probed */
> -	if (link->status == DL_STATE_DORMANT) {
> -		err = -EPROBE_DEFER;
> -		goto out;
> -	}
> -
> -skip_reset:
>  	/* find phy node */
>  	phy_node = of_parse_phandle(dev->of_node, "phys", 0);
> +	if (!phy_node)
> +		return dev_err_probe(dev, -ENOENT, "No PHY node
> found\n");
>  
> -	if (phy_node) {
> -		phy_pdev = of_find_device_by_node(phy_node);
> -		if (!phy_pdev)
> -			goto skip_phy;
> -		phy_dev = &phy_pdev->dev;
> +	phy_pdev = of_find_device_by_node(phy_node);
> +	of_node_put(phy_node);
> +	if (!phy_pdev)
> +		return dev_err_probe(dev, -ENODEV, "No PHY device
> found\n");
>  
> -		pm_runtime_set_active(phy_dev);
> -		pm_runtime_enable(phy_dev);
> -		pm_runtime_get_sync(phy_dev);
> +	phy_dev = &phy_pdev->dev;
>  
> -		put_device(phy_dev);
> -		dev_info(dev, "phys node found\n");
> -	} else {
> -		dev_notice(dev, "phys node not found\n");
> +	err = pm_runtime_set_active(phy_dev);
> +	if (err) {
> +		dev_err_probe(dev, err, "Failed to activate PHY
> RPM\n");
> +		goto err_put_phy;
> +	}
> +	pm_runtime_enable(phy_dev);
> +	err = pm_runtime_get_sync(phy_dev);
> +	if (err) {
> +		dev_err_probe(dev, err, "Failed to power on PHY\n");
> +		goto err_put_phy;
>  	}
>  
> -skip_phy:
>  	/* perform generic probe */
>  	err = ufshcd_pltfrm_init(pdev, &ufs_hba_mtk_vops);
>  	if (err) {
> -		dev_err(dev, "probe failed %d\n", err);
> -		goto out;
> +		dev_err_probe(dev, err, "Generic platform probe
> failed\n");
> +		goto err_put_phy;
>  	}
>  
>  	hba = platform_get_drvdata(pdev);
> -	if (!hba)
> -		goto out;
>  
> -	if (phy_node && phy_dev) {
> -		host = ufshcd_get_variant(hba);
> -		host->phy_dev = phy_dev;
> -	}
> +	host = ufshcd_get_variant(hba);
> +	host->phy_dev = phy_dev;
>  
>  	/*
>  	 * Because the default power setting of VSx (the upper layer of
> @@ -2429,9 +2404,11 @@ static int ufs_mtk_probe(struct
> platform_device *pdev)
>  	 */
>  	ufs_mtk_dev_vreg_set_lpm(hba, false);
>  
> -out:
> -	of_node_put(phy_node);
> -	of_node_put(reset_node);
> +	return 0;
> +
> +err_put_phy:
> +	put_device(phy_dev);
> +
>  	return err;
>  }
>  
>