On Fri, 2018-03-16 at 22:21 +0000, Bart Van Assche wrote: > On Fri, 2018-03-16 at 15:00 -0700, James Bottomley wrote: > > > > On Fri, 2018-03-16 at 10:40 -0700, Bart Van Assche wrote: > > > > > > @@ -1050,7 +1050,22 @@ static int scsi_send_eh_cmnd(struct > > > scsi_cmnd > > > *scmd, unsigned char *cmnd, > > > > > > scsi_log_send(scmd); > > > scmd->scsi_done = scsi_eh_done; > > > - rtn = shost->hostt->queuecommand(shost, scmd); > > > + mutex_lock(&sdev->state_mutex); > > > + while (sdev->sdev_state == SDEV_QUIESCE && timeleft > 0) > > > { > > > + mutex_unlock(&sdev->state_mutex); > > > + SCSI_LOG_ERROR_RECOVERY(5, > > > sdev_printk(KERN_DEBUG, > > > sdev, > > > + "%s: state %d <> %d\n", __func__, sdev- > > > > > > > > sdev_state, > > > > > > + SDEV_QUIESCE)); > > > + delay = min(timeleft, stall_for); > > > + timeleft -= delay; > > > + msleep(jiffies_to_msecs(delay)); > > > + mutex_lock(&sdev->state_mutex); > > > + } > > > > What's the point of this loop? if you eliminate it, you still get > > exactly the same msleep from the stall_for retry processing. > > Hello James, > > The purpose of that loop is to check the SCSI device state every > "stall_for" jiffies and to avoid that more than "timeleft" jiffies is > spent on waiting. I know what the loop does; the the question I was asking is doesn't setting rtn instead of calling ->queuecommand() achieve the same thing? James