mac address issue of tp-link wdr3600 and archer c7-v2

[e9hack]

Hi,

I'm using two tp-link routers. Both are using the same mac address for one eth and one wlan interface:

archer c7-v2:
uboot	60:xx:xx:xx:xx:E6
eth0	60:xx:xx:xx:xx:E7
eth1	60:xx:xx:xx:xx:E6
wlan0	60:xx:xx:xx:xx:E4	5G
wlan1	60:xx:xx:xx:xx:E6	2.4G

wdr3600:
uboot	C0:xx:xx:xx:xx:60
eth0	C0:xx:xx:xx:xx:60
wlan0	C0:xx:xx:xx:xx:5F	2.4G
wlan1	C0:xx:xx:xx:xx:60	5G

It looks like if an address decrement is missing for one wlan interface. I don't know if this can trigger a problem.

With a small patch, I did fix it for both of my routers:

--- a/target/linux/ath79/dts/ar9344_tplink_tl-wdr4300.dtsi
+++ b/target/linux/ath79/dts/ar9344_tplink_tl-wdr4300.dtsi
@@ -82,6 +82,7 @@
  &ath9k {
         nvmem-cells = <&macaddr_uboot_1fc00>;
         nvmem-cell-names = "mac-address";
+       mac-address-increment = <(-2)>;
  };

  &wmac {
--- a/target/linux/ath79/dts/qca9558_tplink_archer-c7-v2.dts
+++ b/target/linux/ath79/dts/qca9558_tplink_archer-c7-v2.dts
@@ -64,6 +64,7 @@

         nvmem-cells = <&macaddr_uboot_1fc00>;
         nvmem-cell-names = "mac-address";
+       mac-address-increment = <(-1)>;
  };

  &uboot {

Now I get:

archer c7-v2:
eth0	60:xx:xx:xx:xx:E7
eth1	60:xx:xx:xx:xx:E6
wlan0	60:xx:xx:xx:xx:E4	5G
wlan1	60:xx:xx:xx:xx:E5	2.4G

wdr3600:
eth0	C0:xx:xx:xx:xx:60
wlan0	C0:xx:xx:xx:xx:5F	2.4G
wlan1	C0:xx:xx:xx:xx:5E	5G

I don't know, if exist some rule whether decrement by -1/-2 shall refer to the interface number or to the frequency.

Regards,
Hartmut