ieee1394: add quirk fix for Freecom HDD

According to http://bugzilla.kernel.org/show_bug.cgi?id=12206, Freecom
FireWire Hard Drive 1TB reports max_rom=2 but returns garbage if block
read requests are used to read the config ROM.  Force max_rom=0 to limit
them to quadlet read requests.
Reported-by: Christian Mueller <cm1@mumac.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/ieee1394/nodemgr.c

@@ -115,8 +115,14 @@ static int nodemgr_bus_read(struct csr1212_csr *csr, u64 addr, u16 length,
 	return error;
 }
 
+#define OUI_FREECOM_TECHNOLOGIES_GMBH 0x0001db
+
 static int nodemgr_get_max_rom(quadlet_t *bus_info_data, void *__ci)
 {
+	/* Freecom FireWire Hard Drive firmware bug */
+	if (be32_to_cpu(bus_info_data[3]) >> 8 == OUI_FREECOM_TECHNOLOGIES_GMBH)
+		return 0;
+
 	return (be32_to_cpu(bus_info_data[2]) >> 8) & 0x3;
 }