MIPS: Octeon: device_tree_init: don't fill mac if already set

Don't fill MAC address if it's already set. This allows DTB to
override the bootinfo.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12589/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/cavium-octeon/octeon-platform.c

@@ -13,6 +13,7 @@
 #include <linux/i2c.h>
 #include <linux/usb.h>
 #include <linux/dma-mapping.h>
+#include <linux/etherdevice.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
@@ -525,10 +526,17 @@ static void __init octeon_fdt_set_phy(int eth, int phy_addr)
 
 static void __init octeon_fdt_set_mac_addr(int n, u64 *pmac)
 {
+	const u8 *old_mac;
+	int old_len;
 	u8 new_mac[6];
 	u64 mac = *pmac;
 	int r;
 
+	old_mac = fdt_getprop(initial_boot_params, n, "local-mac-address",
+			      &old_len);
+	if (!old_mac || old_len != 6 || is_valid_ether_addr(old_mac))
+		return;
+
 	new_mac[0] = (mac >> 40) & 0xff;
 	new_mac[1] = (mac >> 32) & 0xff;
 	new_mac[2] = (mac >> 24) & 0xff;