scsi: lpfc: Add MDS Diagnostic support.

Added code to support Cisco MDS loopback diagnostic. The diagnostics run
various loopbacks including one which loops-back frame through the
driver.

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>
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index dcc9b38..3ffcd92 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -701,7 +701,8 @@ lpfc_work_done(struct lpfc_hba *phba)
 			/* Set the lpfc data pending flag */
 			set_bit(LPFC_DATA_READY, &phba->data_flags);
 		} else {
-			if (phba->link_state >= LPFC_LINK_UP) {
+			if (phba->link_state >= LPFC_LINK_UP ||
+			    phba->link_flag & LS_MDS_LOOPBACK) {
 				pring->flag &= ~LPFC_DEFERRED_RING_EVENT;
 				lpfc_sli_handle_slow_ring_event(phba, pring,
 								(status &