Hi,

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: e3ce73d (scsi: ufs: fix bugs related to null pointer access and array size)

This code was inserted before platform_set_drvdata in 6269473 [SCSI] ufs: Add runtime PM support for UFS host controller driver. Why do you point to e3ce73d?

Thanks, Avri

Cc: stable@vger.kernel.org Signed-off-by: Stanley Chu stanley.chu@mediatek.com

---

drivers/scsi/ufs/ufshcd-pltfrm.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)

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: -- 2.18.0