From e96647dde8106696c037aeb994e996393560bcd2 Mon Sep 17 00:00:00 2001
From: gonzo <gonzo@FreeBSD.org>
Date: Fri, 27 Oct 2017 21:22:38 +0000
Subject: [PATCH] Fix MAC address detection regression introduced by r324184

To accomodate all variaties of Pi DTS files floating around
we look for MAC address property either in DTS node for
USB ethernet (if it exists) or at predefined path
".../usb/hub/ethernet".

After r324184 smsc_fdt_find_eth_node started to return node
with compatibility string "usb424,ec00" as an eth node.
In imported GNU dts files this node still does not have
MAC address related property, and therefor following check for
"mac-address" and "local-mac-address" fails.

To make this logic more robust do not just search for the node
but also make sure it has required property, so if node with
accepted compatibility string exists but doesn't have the
property we fall back to looking for hardoded path mentioned above.
---
 sys/dev/usb/net/if_smsc.c | 62 ++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 23 deletions(-)

diff --git a/sys/dev/usb/net/if_smsc.c b/sys/dev/usb/net/if_smsc.c
index 4fe9dea1e493..1b4c2e353740 100644
--- a/sys/dev/usb/net/if_smsc.c
+++ b/sys/dev/usb/net/if_smsc.c
@@ -1637,6 +1637,37 @@ smsc_fdt_find_eth_node_by_path(phandle_t start)
 	return (-1);
 }
 
+/*
+ * Look through known names that can contain mac address
+ * return 0 if valid MAC address has been found
+ */
+static int
+smsc_fdt_read_mac_property(phandle_t node, unsigned char *mac)
+{
+	int len;
+
+	/* Check if there is property */
+	if ((len = OF_getproplen(node, "local-mac-address")) > 0) {
+		if (len != ETHER_ADDR_LEN)
+			return (EINVAL);
+
+		OF_getprop(node, "local-mac-address", mac,
+		    ETHER_ADDR_LEN);
+		return (0);
+	}
+
+	if ((len = OF_getproplen(node, "mac-address")) > 0) {
+		if (len != ETHER_ADDR_LEN)
+			return (EINVAL);
+
+		OF_getprop(node, "mac-address", mac,
+		    ETHER_ADDR_LEN);
+		return (0);
+	}
+
+	return (ENXIO);
+}
+
 /**
  * Get MAC address from FDT blob.  Firmware or loader should fill
  * mac-address or local-mac-address property.  Returns 0 if MAC address
@@ -1646,37 +1677,22 @@ static int
 smsc_fdt_find_mac(unsigned char *mac)
 {
 	phandle_t node, root;
-	int len;
 
 	root = OF_finddevice("/");
 	node = smsc_fdt_find_eth_node(root);
+	if (node != -1) {
+		if (smsc_fdt_read_mac_property(node, mac) == 0)
+			return (0);
+	}
+
 	/*
 	 * If it's not FreeBSD FDT blob for RPi, try more
 	 *     generic .../usb/hub/ethernet
 	 */
-	if (node == -1)
-		node = smsc_fdt_find_eth_node_by_path(root);
+	node = smsc_fdt_find_eth_node_by_path(root);
 
-	if (node != -1) {
-		/* Check if there is property */
-		if ((len = OF_getproplen(node, "local-mac-address")) > 0) {
-			if (len != ETHER_ADDR_LEN)
-				return (EINVAL);
-
-			OF_getprop(node, "local-mac-address", mac,
-			    ETHER_ADDR_LEN);
-			return (0);
-		}
-
-		if ((len = OF_getproplen(node, "mac-address")) > 0) {
-			if (len != ETHER_ADDR_LEN)
-				return (EINVAL);
-
-			OF_getprop(node, "mac-address", mac,
-			    ETHER_ADDR_LEN);
-			return (0);
-		}
-	}
+	if (node != -1)
+		return smsc_fdt_read_mac_property(node, mac);
 
 	return (ENXIO);
 }