Re: [RFC PATCH v1] scsi: ufs: Quiesce all scsi devices before shutdown

[Bart Van Assche]

On 2020-07-01 18:32, Stanley Chu wrote:
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 59358bb75014..cadfa9006972 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -8599,10 +8599,14 @@ 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;
>  
> +	list_for_each_entry(starget, &hba->host->__targets, siblings)
> +		scsi_target_quiesce(starget);
> +
>  	if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba))
>  		goto out;

Please add a comment above the list_for_each_entry() loop that explains
that there is no matching scsi_target_unquiesce() call and also that
SCSI commands queued after the scsi_target_quiesce() call returned will
block until blk_cleanup_queue() is called (see also the blk_queue_dying()
check in blk_queue_enter()).

Thanks,

Bart.