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

Chaotian Jing (井朝天)
2025-11-05T06:28:58Z

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@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;
> }
>
>