Mandatory VLAN Tagging on mv88e6085 since f1158f

[Etienne Champetier]

Hi Quigfang,

I've started testing 21.02 and updated my Turris Omnia from 19.07.
In 19.07 I had a usable configuration (maybe with some bugs ;) )
without VLAN tagging with lanX port simply bridged to different wifi.
Since 21.02 I have the following errors in dmesg
[   15.739908] mv88e6085 f1072004.mdio-mii:10: p3: hw VLAN 1 already
used by port 4 in br-lan
[   15.784026] mv88e6085 f1072004.mdio-mii:10 lan3: failed to
initialize vlan filtering on this port

Reading https://forum.openwrt.org/t/kernel-5-4-96-broke-untagged-dsa-vlans-on-my-mvebu-routers/88361,
I understand that a working workaround is to use VLAN tagging
explicitly, but I'm wondering if
- this is just a limitation of your hack
(https://github.com/openwrt/openwrt/blob/f1158fbcf63c190fb4f7686075ab99f2aee98a92/target/linux/generic/hack-5.4/710-net-dsa-mv88e6xxx-default-VID-1.patch)
- or if this hack is really mandatory and this switch is just plain
unusable without VLAN tagging

Thanks
Etienne

P.S: here is part of my pretty simple config:

/etc/config/network
config interface 'lan'
    option type 'bridge'
    option proto 'static'
...
    option ifname 'lan4'

config interface 'lan_iot'
    option proto 'static'
...
    option ifname 'lan3'
    option type 'bridge'

/etc/config/wireless
config wifi-iface 'default_radio0'
    option device 'radio0'
    option network 'lan'
    option mode 'ap'
...

config wifi-iface 'default_radio1'
    option device 'radio1'
    option mode 'ap'
    option network 'lan_iot'
...

And a bigger part of dmesg ouput
[   15.686385] mv88e6085 f1072004.mdio-mii:10 lan3: configuring for
phy/gmii link mode
[   15.700429] 8021q: adding VLAN 0 to HW filter on device lan3
[   15.706521] br-lan_iot: port 1(lan3) entered blocking state
[   15.712126] br-lan_iot: port 1(lan3) entered disabled state
[   15.726871] device lan3 entered promiscuous mode
[   15.739908] mv88e6085 f1072004.mdio-mii:10: p3: hw VLAN 1 already
used by port 4 in br-lan
[   15.784026] mv88e6085 f1072004.mdio-mii:10 lan3: failed to
initialize vlan filtering on this port
[   15.820888] br-lan_iot: port 1(lan3) entered blocking state
[   15.826485] br-lan_iot: port 1(lan3) entered disabled state
[   15.838961] mv88e6085 f1072004.mdio-mii:10: p3: hw VLAN 1 already
used by port 4 in br-lan
[   15.884020] mv88e6085 f1072004.mdio-mii:10 lan3: failed to
initialize vlan filtering on this port
[   15.920849] br-lan_iot: port 1(lan3) entered blocking state
[   15.926442] br-lan_iot: port 1(lan3) entered disabled state
[   15.938179] mv88e6085 f1072004.mdio-mii:10: p3: hw VLAN 1 already
used by port 4 in br-lan
[   15.984020] mv88e6085 f1072004.mdio-mii:10 lan3: failed to
initialize vlan filtering on this port
[   16.020844] br-lan_iot: port 1(lan3) entered blocking state
[   16.026437] br-lan_iot: port 1(lan3) entered disabled state
[   16.038173] mv88e6085 f1072004.mdio-mii:10: p3: hw VLAN 1 already
used by port 4 in br-lan
[   16.084036] mv88e6085 f1072004.mdio-mii:10 lan3: failed to
initialize vlan filtering on this port