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 <cang@xxxxxxxxxxxxxx>
> ---
> 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
>
