firewire: fw-ohci: check for misconfigured bus (phyID == 63)

Check NodeID.nodeNumber as per OHCI 1.1 clause 7.2.3.2.  See also IEEE
1394a table 5B-1.

Also, demote the "node ID not valid" message from error to notification
as it is not an error condition.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index ec70c9f..2f307c4 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -917,10 +917,15 @@
 
 	reg = reg_read(ohci, OHCI1394_NodeID);
 	if (!(reg & OHCI1394_NodeID_idValid)) {
-		fw_error("node ID not valid, new bus reset in progress\n");
+		fw_notify("node ID not valid, new bus reset in progress\n");
 		return;
 	}
-	ohci->node_id = reg & 0xffff;
+	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
+		fw_notify("malconfigured bus\n");
+		return;
+	}
+	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
+			       OHCI1394_NodeID_nodeNumber);
 
 	/*
 	 * The count in the SelfIDCount register is the number of