UFS error handling now is doing more than just re-probing, but also sending
scsi cmds, e.g., for clearing UACs, and recovering runtime PM error, which
may change runtime status of scsi devices. To protect system suspend/resume
from being disturbed by error handling, move the host_sem from wl pm ops
to ufshcd_suspend_prepare() and ufshcd_resume_complete().
Signed-off-by: Can Guo <[email protected]>
---
drivers/scsi/ufs/ufshcd.c | 8 +++-----
drivers/scsi/ufs/ufshcd.h | 2 +-
2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c418a19..861942b 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -9060,16 +9060,13 @@ static int ufshcd_wl_suspend(struct device *dev)
ktime_t start = ktime_get();
hba = shost_priv(sdev->host);
- down(&hba->host_sem);
if (pm_runtime_suspended(dev))
goto out;
ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
- if (ret) {
+ if (ret)
dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
- up(&hba->host_sem);
- }
out:
if (!ret)
@@ -9102,7 +9099,6 @@ static int ufshcd_wl_resume(struct device *dev)
hba->curr_dev_pwr_mode, hba->uic_link_state);
if (!ret)
hba->is_wl_sys_suspended = false;
- up(&hba->host_sem);
return ret;
}
#endif
@@ -9665,6 +9661,7 @@ void ufshcd_resume_complete(struct device *dev)
ufshcd_rpmb_rpm_put(hba);
hba->rpmb_complete_put = false;
}
+ up(&hba->host_sem);
}
EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
@@ -9691,6 +9688,7 @@ int ufshcd_suspend_prepare(struct device *dev)
ufshcd_rpmb_rpm_get_sync(hba);
hba->rpmb_complete_put = true;
}
+ down(&hba->host_sem);
return 0;
}
EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index eaebb4e..47da47c 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -693,7 +693,7 @@ struct ufs_hba_monitor {
* @ee_ctrl_mask: Exception event control mask
* @is_powered: flag to check if HBA is powered
* @shutting_down: flag to check if shutdown has been invoked
- * @host_sem: semaphore used to serialize concurrent contexts
+ * @host_sem: semaphore used to avoid concurrency of contexts
* @eh_wq: Workqueue that eh_work works on
* @eh_work: Worker to handle UFS errors that require s/w attention
* @eeh_work: Worker to handle exception events
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
On 10/06/21 7:43 am, Can Guo wrote:
> UFS error handling now is doing more than just re-probing, but also sending
> scsi cmds, e.g., for clearing UACs, and recovering runtime PM error, which
> may change runtime status of scsi devices. To protect system suspend/resume
> from being disturbed by error handling, move the host_sem from wl pm ops
> to ufshcd_suspend_prepare() and ufshcd_resume_complete().
Have you checked whether error handling might actually be needed after
ufshcd_suspend_prepare()?
Wouldn't this complexity go away if we just did recovery
directly in __ufshcd_wl_suspend() and __ufshcd_wl_resume()?
>
> Signed-off-by: Can Guo <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd.c | 8 +++-----
> drivers/scsi/ufs/ufshcd.h | 2 +-
> 2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index c418a19..861942b 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -9060,16 +9060,13 @@ static int ufshcd_wl_suspend(struct device *dev)
> ktime_t start = ktime_get();
>
> hba = shost_priv(sdev->host);
> - down(&hba->host_sem);
>
> if (pm_runtime_suspended(dev))
> goto out;
>
> ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
> - if (ret) {
> + if (ret)
> dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
> - up(&hba->host_sem);
> - }
>
> out:
> if (!ret)
> @@ -9102,7 +9099,6 @@ static int ufshcd_wl_resume(struct device *dev)
> hba->curr_dev_pwr_mode, hba->uic_link_state);
> if (!ret)
> hba->is_wl_sys_suspended = false;
> - up(&hba->host_sem);
> return ret;
> }
> #endif
> @@ -9665,6 +9661,7 @@ void ufshcd_resume_complete(struct device *dev)
> ufshcd_rpmb_rpm_put(hba);
> hba->rpmb_complete_put = false;
> }
> + up(&hba->host_sem);
> }
> EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
>
> @@ -9691,6 +9688,7 @@ int ufshcd_suspend_prepare(struct device *dev)
> ufshcd_rpmb_rpm_get_sync(hba);
> hba->rpmb_complete_put = true;
> }
> + down(&hba->host_sem);
> return 0;
> }
> EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index eaebb4e..47da47c 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -693,7 +693,7 @@ struct ufs_hba_monitor {
> * @ee_ctrl_mask: Exception event control mask
> * @is_powered: flag to check if HBA is powered
> * @shutting_down: flag to check if shutdown has been invoked
> - * @host_sem: semaphore used to serialize concurrent contexts
> + * @host_sem: semaphore used to avoid concurrency of contexts
> * @eh_wq: Workqueue that eh_work works on
> * @eh_work: Worker to handle UFS errors that require s/w attention
> * @eeh_work: Worker to handle exception events
>
Hi Adrian,
On 2021-06-10 21:32, Adrian Hunter wrote:
> On 10/06/21 7:43 am, Can Guo wrote:
>> UFS error handling now is doing more than just re-probing, but also
>> sending
>> scsi cmds, e.g., for clearing UACs, and recovering runtime PM error,
>> which
>> may change runtime status of scsi devices. To protect system
>> suspend/resume
>> from being disturbed by error handling, move the host_sem from wl pm
>> ops
>> to ufshcd_suspend_prepare() and ufshcd_resume_complete().
>
> Have you checked whether error handling might actually be needed after
> ufshcd_suspend_prepare()?
I intend to make it this (simple) way - if error handling is invoked
during system suspend/resume, it should just wait until system resume
is finished. suspend/resume does not count on error handling, if
suspend/resume
run into errors, they just fail and bail.
>
> Wouldn't this complexity go away if we just did recovery
> directly in __ufshcd_wl_suspend() and __ufshcd_wl_resume()?
>
Please kindly check my reply in patch #5.
Thanks,
Can Guo.
>>
>> Signed-off-by: Can Guo <[email protected]>
>> ---
>> drivers/scsi/ufs/ufshcd.c | 8 +++-----
>> drivers/scsi/ufs/ufshcd.h | 2 +-
>> 2 files changed, 4 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index c418a19..861942b 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -9060,16 +9060,13 @@ static int ufshcd_wl_suspend(struct device
>> *dev)
>> ktime_t start = ktime_get();
>>
>> hba = shost_priv(sdev->host);
>> - down(&hba->host_sem);
>>
>> if (pm_runtime_suspended(dev))
>> goto out;
>>
>> ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
>> - if (ret) {
>> + if (ret)
>> dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>> - up(&hba->host_sem);
>> - }
>>
>> out:
>> if (!ret)
>> @@ -9102,7 +9099,6 @@ static int ufshcd_wl_resume(struct device *dev)
>> hba->curr_dev_pwr_mode, hba->uic_link_state);
>> if (!ret)
>> hba->is_wl_sys_suspended = false;
>> - up(&hba->host_sem);
>> return ret;
>> }
>> #endif
>> @@ -9665,6 +9661,7 @@ void ufshcd_resume_complete(struct device *dev)
>> ufshcd_rpmb_rpm_put(hba);
>> hba->rpmb_complete_put = false;
>> }
>> + up(&hba->host_sem);
>> }
>> EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
>>
>> @@ -9691,6 +9688,7 @@ int ufshcd_suspend_prepare(struct device *dev)
>> ufshcd_rpmb_rpm_get_sync(hba);
>> hba->rpmb_complete_put = true;
>> }
>> + down(&hba->host_sem);
>> return 0;
>> }
>> EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index eaebb4e..47da47c 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -693,7 +693,7 @@ struct ufs_hba_monitor {
>> * @ee_ctrl_mask: Exception event control mask
>> * @is_powered: flag to check if HBA is powered
>> * @shutting_down: flag to check if shutdown has been invoked
>> - * @host_sem: semaphore used to serialize concurrent contexts
>> + * @host_sem: semaphore used to avoid concurrency of contexts
>> * @eh_wq: Workqueue that eh_work works on
>> * @eh_work: Worker to handle UFS errors that require s/w attention
>> * @eeh_work: Worker to handle exception events
>>
On 6/9/21 9:43 PM, Can Guo wrote:
> UFS error handling now is doing more than just re-probing, but also sending
> scsi cmds, e.g., for clearing UACs, and recovering runtime PM error, which
> may change runtime status of scsi devices. To protect system suspend/resume
> from being disturbed by error handling, move the host_sem from wl pm ops
> to ufshcd_suspend_prepare() and ufshcd_resume_complete().
If lock_system_sleep() and unlock_system_sleep() would be used in the
error handler, would that allow to remove host_sem?
Thanks,
Bart.
On 2021-06-12 05:00, Bart Van Assche wrote:
> On 6/9/21 9:43 PM, Can Guo wrote:
>> UFS error handling now is doing more than just re-probing, but also
>> sending
>> scsi cmds, e.g., for clearing UACs, and recovering runtime PM error,
>> which
>> may change runtime status of scsi devices. To protect system
>> suspend/resume
>> from being disturbed by error handling, move the host_sem from wl pm
>> ops
>> to ufshcd_suspend_prepare() and ufshcd_resume_complete().
>
> If lock_system_sleep() and unlock_system_sleep() would be used in the
> error handler, would that allow to remove host_sem?
Please kindly check my reply in patch #5.
Thanks,
Can Guo.
>
> Thanks,
>
> Bart.