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@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
