Messages in this thread | | | Date | Fri, 11 Jun 2021 11:06:32 +0800 | From | Can Guo <> | Subject | Re: [PATCH v3 7/9] scsi: ufs: Let host_sem cover the entire system suspend/resume |
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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 <cang@codeaurora.org> >> --- >> 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 >>
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