[LEDE-DEV] Help needed: IP175D + RT3662 issues on a "new" device

[antonio rossi]

Hi everybody,

i'll try to make this as short as possible despite the large amount of 
information needed to describe the issue:

i am working on adding support to LEDE/OpenWRT for DIR-815 A1, it's a 
RT3662+RT3092 device with an infamous IP175D switch IC.
i managed to get everything working properly, save for the fact that 
network (both ethernet&wifi) works only after the stock bootloader 
does some funky stuff to set up the internal cpu port and/or switch 
to receive images via TFTP.

this basically means that when the bootloader receives something via 
TFTP then any image booted (either initramfs or from flash) works properly,
while a squashfs image booted from the internal flash (so the bootloader 
does not set up cpu port/switch) doesn't. 
the boot log of working and non-working states are basically identical. the 
switch is recognized and everything. i've tried every possible combination of 
parameters in the DTS file to no avail.
I also investigated GPIO pins, but the only pin that has somewhat of an effect 
is GPIO24 which is connected to the switch reset pin, and it has no effect on 
the issue itself (it just resets the switch that then needs to be reconfigured
with the vlans and such)
What catches my interest are those few lines from the bootloader that says


1.set ge1 as normal mode


1.set ge1 as mii mode


enable turbo mii


Using Eth0 (10/100-M) device


i am guessing ge1 refers to the gigabit ethernet cpu port and the turbo mii,
well, i can't set that mode, just normal mii. it's weird because changing
phy-mode in the DTS actually affects the cpu port and switch but there is 
still something missing to make it work without bootloader/stock rom 
intervention.

here are the bootlog pastebins, both of working and non working state
(in this order).
any help is appreciated.

http://pastebin.com/rNwewZ8J
http://pastebin.com/Gw9DNfFZ

here is the DTS
http://pastebin.com/iLSbw9gJ

here is the swconfig output (identical in both working and non-working state)
http://pastebin.com/iBK47i9m

best regards,
Bracco