[SCSI] libfc: adds flogi retry in case DID is zero in RJT

Sometimes switch in NPV mode rejects flogi request with DID
zero and in that case flogi is not tried again and port
remains offline, so this patch validates DID for non zero
along with only ACC response to allow flogi retry
for RJT with DID=0 also succeed FLOGI in next try.

Signed-off-by: Vasu Dev <[e-mail]>
Signed-off-by: Robert Love <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/libfc/fc_lport.c

···
 	}
 
 	did = fc_frame_did(fp);
-
-	if (!did) {
-		FC_LPORT_DBG(lport, "Bad FLOGI response\n");
-		goto out;
-	}
-
-	if (fc_frame_payload_op(fp) == ELS_LS_ACC) {
+	if (fc_frame_payload_op(fp) == ELS_LS_ACC && did) {
 		flp = fc_frame_payload_get(fp, sizeof(*flp));
 		if (flp) {
 			mfs = ntohs(flp->fl_csp.sp_bb_data) &
···
 				fc_lport_enter_dns(lport);
 			}
 		}
-	} else
+	} else {
+		FC_LPORT_DBG(lport, "FLOGI RJT or bad response\n");
 		fc_lport_error(lport, fp);
+	}
 
 out:
 	fc_frame_free(fp);