3.16.75-rc1 review patch. If anyone has any objections, please let me know.
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From: Stanley Chu stanley.chu@mediatek.com
commit 24e2e7a19f7e4b83d0d5189040d997bce3596473 upstream.
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) 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 [bwh: Backported to 3.16: - ufshcd_pltrfm_probe() doesn't allocate or free the host structure - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/scsi/ufs/ufshcd-pltfrm.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c @@ -150,22 +150,19 @@ static int ufshcd_pltfrm_probe(struct pl goto out; }
- pm_runtime_set_active(&pdev->dev); - pm_runtime_enable(&pdev->dev); - err = ufshcd_init(dev, &hba, mmio_base, irq); if (err) { dev_err(dev, "Intialization failed\n"); - goto out_disable_rpm; + goto out; }
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); out: return err; }