FAILED: patch "[PATCH] scsi: ufs: Avoid runtime suspend possibly being blocked" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 24e2e7a19f7e4b83d0d5189040d997bce3596473 Mon Sep 17 00:00:00 2001
From: Stanley Chu <[email protected]>
Date: Wed, 12 Jun 2019 23:19:05 +0800
Subject: [PATCH] scsi: ufs: Avoid runtime suspend possibly being blocked
forever

UFS runtime suspend can be triggered after pm_runtime_enable() is invoked in ufshcd_pltfrm_init(). However if the first runtime suspend is triggered before binding ufs_hba structure to ufs device structure via platform_set_drvdata(), then UFS runtime suspend will be no longer triggered in the future because its dev->power.runtime_error was set in the first triggering and does not have any chance to be cleared.

To be more clear, dev->power.runtime_error is set if hba is NULL in ufshcd_runtime_suspend() which returns -EINVAL to rpm_callback() where dev->power.runtime_error is set as -EINVAL. In this case, any future rpm_suspend() for UFS device fails because rpm_check_suspend_allowed() fails due to non-zero
dev->power.runtime_error.

To resolve this issue, make sure the first UFS runtime suspend get valid "hba" in ufshcd_runtime_suspend(): Enable UFS runtime PM only after hba is successfully bound to UFS device structure.

index 8a74ec30c3d2..d7d521b394c3 100644
@@ -430,24 +430,21 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
 		goto dealloc_host;
 	}
 
-	pm_runtime_set_active(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-
 	ufshcd_init_lanes_per_dir(hba);
 
 	err = ufshcd_init(hba, mmio_base, irq);
 	if (err) {
 		dev_err(dev, "Initialization failed\n");
-		goto out_disable_rpm;
+		goto dealloc_host;
 	}
 
 	platform_set_drvdata(pdev, hba);
 
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
 	return 0;
 
-out_disable_rpm:
-	pm_runtime_disable(&pdev->dev);
-	pm_runtime_set_suspended(&pdev->dev);
 dealloc_host:
 	ufshcd_dealloc_host(hba);
 out: