diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index fd4c025a3f70..0547253d16fe 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -153,8 +153,25 @@ static void get_ids(const u32 *directory, int *id)
 
 static void get_modalias_ids(const struct fw_unit *unit, int *id)
 {
-	get_ids(&fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET], id);
-	get_ids(unit->directory, id);
+	const u32 *root_directory = &fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET];
+	const u32 *directories[] = {NULL, NULL, NULL};
+	const u32 *vendor_directory;
+	int i;
+
+	directories[0] = root_directory;
+
+	// Legacy layout of configuration ROM described in Annex 1 of 'Configuration ROM for AV/C
+	// Devices 1.0 (December 12, 2000, 1394 Trading Association, TA Document 1999027)'.
+	vendor_directory = search_directory(root_directory, CSR_VENDOR);
+	if (!vendor_directory) {
+		directories[1] = unit->directory;
+	} else {
+		directories[1] = vendor_directory;
+		directories[2] = unit->directory;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i)
+		get_ids(directories[i], id);
 }
 
 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
diff --git a/drivers/firewire/device-attribute-test.c b/drivers/firewire/device-attribute-test.c
index da2a4a09bf84..2f123c6b0a16 100644
--- a/drivers/firewire/device-attribute-test.c
+++ b/drivers/firewire/device-attribute-test.c
@@ -178,7 +178,7 @@ static void device_attr_legacy_avc(struct kunit *test)
 	};
 	struct device *node_dev = (struct device *)&node.device;
 	struct device *unit0_dev = (struct device *)&unit0.device;
-	static const int unit0_expected_ids[] = {0x00012345, 0x00000000, 0x00abcdef, 0x00543210};
+	static const int unit0_expected_ids[] = {0x00012345, 0x00fedcba, 0x00abcdef, 0x00543210};
 	char *buf = kunit_kzalloc(test, PAGE_SIZE, GFP_KERNEL);
 	int ids[4] = {0, 0, 0, 0};