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 stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 24e2e7a19f7e4b83d0d5189040d997bce3596473 Mon Sep 17 00:00:00 2001
From: Stanley Chu stanley.chu@mediatek.com 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.
Fixes: 62694735ca95 ([SCSI] ufs: Add runtime PM support for UFS host controller driver) Cc: stable@vger.kernel.org Signed-off-by: Stanley Chu stanley.chu@mediatek.com Reviewed-by: Avri Altman avri.altman@wdc.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com
diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c index 8a74ec30c3d2..d7d521b394c3 100644 --- a/drivers/scsi/ufs/ufshcd-pltfrm.c +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c @@ -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: