scsi: ufs: host: mediatek: Correct system PM flow

Refine the system power management (PM) flow by skipping low power mode
(LPM) and MTCMOS settings if runtime PM is already applied. Prevent
redundant operations to ensure a more efficient PM process.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: ptr324

drivers/ufs/host/ufs-mediatek.c

@@ -2304,27 +2304,38 @@ static int ufs_mtk_system_suspend(struct device *dev)
 
 	ret = ufshcd_system_suspend(dev);
 	if (ret)
-		return ret;
+		goto out;
+
+	if (pm_runtime_suspended(hba->dev))
+		goto out;
 
 	ufs_mtk_dev_vreg_set_lpm(hba, true);
 
 	if (ufs_mtk_is_rtff_mtcmos(hba))
 		ufs_mtk_mtcmos_ctrl(false, res);
 
-	return 0;
+out:
+	return ret;
 }
 
 static int ufs_mtk_system_resume(struct device *dev)
 {
+	int ret = 0;
 	struct ufs_hba *hba = dev_get_drvdata(dev);
 	struct arm_smccc_res res;
 
+	if (pm_runtime_suspended(hba->dev))
+		goto out;
+
 	ufs_mtk_dev_vreg_set_lpm(hba, false);
 
 	if (ufs_mtk_is_rtff_mtcmos(hba))
 		ufs_mtk_mtcmos_ctrl(true, res);
 
-	return ufshcd_system_resume(dev);
+out:
+	ret = ufshcd_system_resume(dev);
+
+	return ret;
 }
 #endif