diff mbox series

scsi: ufs: Fix a bug in ufshcd_system_resume()

Message ID 20201110085537.2889-1-yang.yang@vivo.com
State New
Headers show
Series scsi: ufs: Fix a bug in ufshcd_system_resume() | expand

Commit Message

Yang Yang Nov. 10, 2020, 8:55 a.m. UTC
During system resume, ufshcd_system_resume() won't resume UFS host if
runtime suspended. After that, scsi_bus_resume() try to set SCSI host's
RPM status to RPM_ACTIVE, this will fail because UFS host's RPM status
is still RPM_SUSPENDED. So fix it.

    scsi host0: scsi_runtime_suspend()
		ufshcd_runtime_suspend()
    scsi host0: scsi_bus_suspend()
		ufshcd_system_suspend()
    ----------------------------------
		ufshcd_pltfrm_resume()
    scsi host0: scsi_bus_resume()
    scsi host0: scsi_bus_resume_common()
    scsi host0: pm_runtime_set_active(dev)

    scsi host0: runtime PM trying to activate child device host0 but parent
    (8800000.ufshc) is not active

Fixes: 57d104c153d3 ("ufs: add UFS power management support")
Signed-off-by: Yang Yang <yang.yang@vivo.com>
---
 drivers/scsi/ufs/ufshcd.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Comments

Can Guo Nov. 13, 2020, 5:05 a.m. UTC | #1
On 2020-11-10 16:55, Yang Yang wrote:
> During system resume, ufshcd_system_resume() won't resume UFS host if

> runtime suspended. After that, scsi_bus_resume() try to set SCSI host's

> RPM status to RPM_ACTIVE, this will fail because UFS host's RPM status

> is still RPM_SUSPENDED. So fix it.

> 

>     scsi host0: scsi_runtime_suspend()

> 		ufshcd_runtime_suspend()

>     scsi host0: scsi_bus_suspend()

> 		ufshcd_system_suspend()

>     ----------------------------------

> 		ufshcd_pltfrm_resume()

>     scsi host0: scsi_bus_resume()

>     scsi host0: scsi_bus_resume_common()

>     scsi host0: pm_runtime_set_active(dev)

> 

>     scsi host0: runtime PM trying to activate child device host0 but 

> parent

>     (8800000.ufshc) is not active

> 

> Fixes: 57d104c153d3 ("ufs: add UFS power management support")

> Signed-off-by: Yang Yang <yang.yang@vivo.com>

> ---

>  drivers/scsi/ufs/ufshcd.c | 15 +++++++++------

>  1 file changed, 9 insertions(+), 6 deletions(-)

> 

> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c

> index b8f573a02713..9e666e1ad58c 100644

> --- a/drivers/scsi/ufs/ufshcd.c

> +++ b/drivers/scsi/ufs/ufshcd.c

> @@ -8767,11 +8767,7 @@ int ufshcd_system_resume(struct ufs_hba *hba)

>  	if (!hba)

>  		return -EINVAL;

> 

> -	if (!hba->is_powered || pm_runtime_suspended(hba->dev))

> -		/*

> -		 * Let the runtime resume take care of resuming

> -		 * if runtime suspended.

> -		 */

> +	if (!hba->is_powered)

>  		goto out;

>  	else

>  		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);

> @@ -8779,8 +8775,15 @@ int ufshcd_system_resume(struct ufs_hba *hba)

>  	trace_ufshcd_system_resume(dev_name(hba->dev), ret,

>  		ktime_to_us(ktime_sub(ktime_get(), start)),

>  		hba->curr_dev_pwr_mode, hba->uic_link_state);

> -	if (!ret)

> +	if (!ret) {

>  		hba->is_sys_suspended = false;

> +

> +		if (pm_runtime_suspended(hba->dev)) {

> +			pm_runtime_disable(hba->dev);

> +			pm_runtime_set_active(hba->dev);

> +			pm_runtime_enable(hba->dev);

> +		}

> +	}

>  	return ret;

>  }

>  EXPORT_SYMBOL(ufshcd_system_resume);


It is designed like this - if hba is runtime suspend, do not resume it
during system resume, which is the so called deferred resume feature.
This is to leave the runtime PM management to block layer PM, which
is more power efficiency.

> scsi host0: runtime PM trying to activate child device host0 but parent

> (8800000.ufshc) is not active

The log is not harmful or fatal, maybe just annoying. Do you see real
problem with it? If yes, please share it here.

Thanks,

Can Guo.
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index b8f573a02713..9e666e1ad58c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8767,11 +8767,7 @@  int ufshcd_system_resume(struct ufs_hba *hba)
 	if (!hba)
 		return -EINVAL;
 
-	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
-		/*
-		 * Let the runtime resume take care of resuming
-		 * if runtime suspended.
-		 */
+	if (!hba->is_powered)
 		goto out;
 	else
 		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
@@ -8779,8 +8775,15 @@  int ufshcd_system_resume(struct ufs_hba *hba)
 	trace_ufshcd_system_resume(dev_name(hba->dev), ret,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	if (!ret)
+	if (!ret) {
 		hba->is_sys_suspended = false;
+
+		if (pm_runtime_suspended(hba->dev)) {
+			pm_runtime_disable(hba->dev);
+			pm_runtime_set_active(hba->dev);
+			pm_runtime_enable(hba->dev);
+		}
+	}
 	return ret;
 }
 EXPORT_SYMBOL(ufshcd_system_resume);