scsi: lpfc: Allow set of maximum outstanding SCSI cmd limit for a target

Make the attribute writeable.

Remove the ramp up to logic as its unnecessary, simply set depth.  Add
debug message if depth changed, possibly reducing limit, yet our
outstanding count has yet to catch up with it.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_attr.c

@@ -3464,8 +3464,8 @@ LPFC_VPORT_ATTR_R(lun_queue_depth, 30, 1, 512,
 # tgt_queue_depth:  This parameter is used to limit the number of outstanding
 # commands per target port. Value range is [10,65535]. Default value is 65535.
 */
-LPFC_VPORT_ATTR_R(tgt_queue_depth, 65535, 10, 65535,
-		  "Max number of FCP commands we can queue to a specific target port");
+LPFC_VPORT_ATTR_RW(tgt_queue_depth, 65535, 10, 65535,
+		   "Max number of FCP commands we can queue to a specific target port");
 
 /*
 # hba_queue_depth:  This parameter is used to limit the number of outstanding

drivers/scsi/lpfc/lpfc_scsi.c

@@ -3926,7 +3926,6 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
 	struct lpfc_rport_data *rdata = lpfc_cmd->rdata;
 	struct lpfc_nodelist *pnode = rdata->pnode;
 	struct scsi_cmnd *cmd;
-	int depth;
 	unsigned long flags;
 	struct lpfc_fast_path_event *fast_path_evt;
 	struct Scsi_Host *shost;
@@ -4132,16 +4131,11 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
 		}
 		spin_unlock_irqrestore(shost->host_lock, flags);
 	} else if (pnode && NLP_CHK_NODE_ACT(pnode)) {
-		if ((pnode->cmd_qdepth < vport->cfg_tgt_queue_depth) &&
-		   time_after(jiffies, pnode->last_change_time +
+		if ((pnode->cmd_qdepth != vport->cfg_tgt_queue_depth) &&
+		    time_after(jiffies, pnode->last_change_time +
 			      msecs_to_jiffies(LPFC_TGTQ_INTERVAL))) {
 			spin_lock_irqsave(shost->host_lock, flags);
-			depth = pnode->cmd_qdepth * LPFC_TGTQ_RAMPUP_PCENT
-				/ 100;
-			depth = depth ? depth : 1;
-			pnode->cmd_qdepth += depth;
-			if (pnode->cmd_qdepth > vport->cfg_tgt_queue_depth)
-				pnode->cmd_qdepth = vport->cfg_tgt_queue_depth;
+			pnode->cmd_qdepth = vport->cfg_tgt_queue_depth;
 			pnode->last_change_time = jiffies;
 			spin_unlock_irqrestore(shost->host_lock, flags);
 		}
@@ -4564,9 +4558,32 @@ lpfc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *cmnd)
 	 */
 	if (!ndlp || !NLP_CHK_NODE_ACT(ndlp))
 		goto out_tgt_busy;
-	if (atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth)
+	if (atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth) {
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_FCP_ERROR,
+				 "3377 Target Queue Full, scsi Id:%d Qdepth:%d"
+				 " Pending command:%d"
+				 " WWNN:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x, "
+				 " WWPN:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
+				 ndlp->nlp_sid, ndlp->cmd_qdepth,
+				 atomic_read(&ndlp->cmd_pending),
+				 ndlp->nlp_nodename.u.wwn[0],
+				 ndlp->nlp_nodename.u.wwn[1],
+				 ndlp->nlp_nodename.u.wwn[2],
+				 ndlp->nlp_nodename.u.wwn[3],
+				 ndlp->nlp_nodename.u.wwn[4],
+				 ndlp->nlp_nodename.u.wwn[5],
+				 ndlp->nlp_nodename.u.wwn[6],
+				 ndlp->nlp_nodename.u.wwn[7],
+				 ndlp->nlp_portname.u.wwn[0],
+				 ndlp->nlp_portname.u.wwn[1],
+				 ndlp->nlp_portname.u.wwn[2],
+				 ndlp->nlp_portname.u.wwn[3],
+				 ndlp->nlp_portname.u.wwn[4],
+				 ndlp->nlp_portname.u.wwn[5],
+				 ndlp->nlp_portname.u.wwn[6],
+				 ndlp->nlp_portname.u.wwn[7]);
 		goto out_tgt_busy;
-
+	}
 	lpfc_cmd = lpfc_get_scsi_buf(phba, ndlp);
 	if (lpfc_cmd == NULL) {
 		lpfc_rampdown_queue_depth(phba);