LAN leds not blinking on tx/rx (Archer C7 V4, 18.06-branch)

Hello,

I am currently configuring my firmware for the Archer C7V4. In 18.06 (and I think also on 17.01), the LAN leds can now also be configured from /etc/config/system, in comparison to 15.05, where the leds were just fixed assigned to the switch ports.

I use the default configuration for the leds and they light up correctly on link, but they do not flicker if traffic runs over the ports (the ones for wifi do flicker btw.):

config led 'led_lan1'
        option sysfs 'archer-c7-v4:green:lan4'
        option trigger 'switch0'
        option port_mask '0x04'
        option default '0'
        option name 'LAN1'

I digged a bit into it and could see that the mode setting for the switch0 trigger (in sysfs) is set correctly to link rx tx, however, only link has an effect. If I change to rx tx the led simply stays off.

Judged from the code in ag71xx_ar7240.c it might be an issue that the switch does not report the AR7240_PORT_STATUS_TXFLOW and AR7240_PORT_STATUS_RXFLOW bits correctly, though that is already quite a guess.

Or is it a configuration issue I am simply overlooking?

Thanks for the help!

-Michael