[LEDE-DEV] Newifi D1 Ethernet ports freeze after boot with cable plugin

[Qier LU]

Dear all,

Newifi D1 is a popular router device with MT7621 inside, more detailed
information can be found at WikiDevi .

I have LEDE 17.01.2 running on that device, but experienced a bug with
Ethernet port. The bug is easy to reproduce: just power on or reboot
the device with RJ45 cable plugin. You will find that the LED blinks
when booting, but freezes after boot. The frozen status of LED is
on(wan port), off(lan port), on(lan port) in my situation which have
both 3 ports connected.

But every thing works fine if I power on/reboot the device first, then
plugin the RJ45 cable.

I could not connect to the device via the Ethernet when it is frozen,
but can login via wireless network provided by the device. I have
checked the network status with ifconfig, the RX counter of eth0,
eth0.1 and eth0.2 shows 0 when TX counter seems OK if I ping someone.
I checked the switch as well by command: swconfig dev mt7530 show ,
everything shows 0 on each port, excepted for port 6. No error message
on dmesg for further information.

Some one mentioned it is switch chip driver bug(
https://dev.openwrt.org/ticket/20890?cversion=0&cnum_hist=1 ), but no
further information can be find by google any more.

Devices running another driver named raeth which can be found at
rt-n56u source tree (
https://bitbucket.org/padavan/rt-n56u/src/980d764c7e3e23cd87223e2812723740d6a2d66f/trunk/linux-3.4.x/drivers/net/raeth/?at=master
) seems works fine.

I can provide a device for remote access and debug, could you please
help me to fix it?

Sincerely,
lvqier