On 2020-08-03 03:04, Stanley Chu wrote: > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 307622284239..7cb220b3fde0 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -8640,6 +8640,7 @@ EXPORT_SYMBOL(ufshcd_runtime_idle); > int ufshcd_shutdown(struct ufs_hba *hba) > { > int ret = 0; > + struct scsi_target *starget; > > if (!hba->is_powered) > goto out; > @@ -8647,11 +8648,27 @@ int ufshcd_shutdown(struct ufs_hba *hba) > if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba)) > goto out; > > - if (pm_runtime_suspended(hba->dev)) { > - ret = ufshcd_runtime_resume(hba); > - if (ret) > - goto out; > - } > + /* > + * Let runtime PM framework manage and prevent concurrent runtime > + * operations with shutdown flow. > + */ > + pm_runtime_get_sync(hba->dev); > + > + /* > + * Quiesce all SCSI devices to prevent any non-PM requests sending > + * from block layer during and after shutdown. > + * > + * Here we can not use blk_cleanup_queue() since PM requests > + * (with BLK_MQ_REQ_PREEMPT flag) are still required to be sent > + * through block layer. Therefore SCSI command queued after the > + * scsi_target_quiesce() call returned will block until > + * blk_cleanup_queue() is called. > + * > + * Besides, scsi_target_"un"quiesce (e.g., scsi_target_resume) can > + * be ignored since shutdown is one-way flow. > + */ > + list_for_each_entry(starget, &hba->host->__targets, siblings) > + scsi_target_quiesce(starget); > > ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM); > out: This seems wrong to me. Since ufshcd_shutdown() shuts down the link I think it should call scsi_remove_device() instead of scsi_target_quiesce(). Thanks, Bart.