ath9k: use a random MAC address if the EEPROM address is invalid

Based on OpenWrt patch by Gabor Juhos
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/hw.c

@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/time.h>
 #include <linux/bitops.h>
+#include <linux/etherdevice.h>
 #include <asm/unaligned.h>
 
 #include "hw.h"
@@ -446,8 +447,16 @@ static int ath9k_hw_init_macaddr(struct ath_hw *ah)
 		common->macaddr[2 * i] = eeval >> 8;
 		common->macaddr[2 * i + 1] = eeval & 0xff;
 	}
-	if (sum == 0 || sum == 0xffff * 3)
-		return -EADDRNOTAVAIL;
+	if (!is_valid_ether_addr(common->macaddr)) {
+		ath_err(common,
+			"eeprom contains invalid mac address: %pM\n",
+			common->macaddr);
+
+		random_ether_addr(common->macaddr);
+		ath_err(common,
+			"random mac address will be used: %pM\n",
+			common->macaddr);
+	}
 
 	return 0;
 }