[PATCH v2] scsi: ufs: mediatek: handle mPHY power-on failures

[Pengpeng Hou <hppiscas@163.com>]

The MediaTek helper enables VA09 before powering on the mPHY, but
ignores the PHY result. A failure can leave VA09 enabled and publish
mphy_powered_on as true, so a later power-on attempt is skipped.

Check phy_power_on(), attempt to unwind VA09 on failure, and leave the
state flag unchanged. Propagate the helper result from host
initialization as well as its existing resume caller. Keep the original
PHY error if the supply rollback also fails, and report that rollback
separately.

The issue was found by our static-analysis tool.

Fixes: 561e3a8726b2 ("scsi: ufs-mediatek: Fix unbalanced clock on/off")
Fixes: cf137b3ea49a ("scsi: ufs-mediatek: Support VA09 regulator operations")
Assisted-by: gpt 5
Signed-off-by: Pengpeng Hou <hppiscas@163.com>
---
Changes since v1:
https://lore.kernel.org/all/20260828092311.10774-1-pengpeng@iscas.ac.cn/
Use err for the rollback result and dev_err() for operation failures, as
Stanley requested.

 drivers/ufs/host/ufs-mediatek.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index 814c1b7343b9..12a6d4138e44 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -509,6 +509,7 @@ static int ufs_mtk_mphy_power_on(struct ufs_hba *hba, bool on)
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 	struct phy *mphy = host->mphy;
 	struct arm_smccc_res res;
+	int err;
 	int ret = 0;
 
 	if (!mphy || !(on ^ host->mphy_powered_on))
@@ -523,7 +524,18 @@ static int ufs_mtk_mphy_power_on(struct ufs_hba *hba, bool on)
 			usleep_range(200, 210);
 			ufs_mtk_va09_pwr_ctrl(res, 1);
 		}
-		phy_power_on(mphy);
+		ret = phy_power_on(mphy);
+		if (ret) {
+			if (ufs_mtk_is_va09_supported(hba)) {
+				ufs_mtk_va09_pwr_ctrl(res, 0);
+				err = regulator_disable(host->reg_va09);
+				if (err)
+					dev_err(hba->dev,
+						"failed to unwind va09: %d\n", err);
+			}
+			dev_err(hba->dev, "failed to enable mphy: %d\n", ret);
+			return ret;
+		}
 	} else {
 		phy_power_off(mphy);
 		if (ufs_mtk_is_va09_supported(hba)) {
@@ -1295,7 +1307,9 @@ static int ufs_mtk_init(struct ufs_hba *hba)
 	 *
 	 * Enable phy clocks specifically here.
 	 */
-	ufs_mtk_mphy_power_on(hba, true);
+	err = ufs_mtk_mphy_power_on(hba, true);
+	if (err)
+		goto out_variant_clear;
 
 	if (ufs_mtk_is_rtff_mtcmos(hba)) {
 		/* First Restore here, to avoid backup unexpected value */

base-commit: 518e5b794c06c0f0eb40df3e202274a66202c137
-- 
2.50.1 (Apple Git-155)