[PATCH v6 11/24] scsi: ufs: mediatek: Rework probe function

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

Remove the ti,syscon-reset cruft, as it was never documented in the
binding, and is not modelling the hardware correctly.

Make PHY mandatory. All the compatibles supported by the binding make it
mandatory.

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.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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 954d6768aa64..fc72bf54ec2a 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -2382,74 +2382,49 @@ 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
@@ -2458,9 +2433,11 @@ 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;
 }
 

-- 
2.52.0