Banana Pi-R1 - kernel 5.6.0 and later broken - b43 DSA

[Gerhard Wiesinger]

Hello,

I'm having troubles with the Banana Pi-R1 router with newer kernels. No 
config changes, config works well since a lot of lernel updates ...
Banana Pi-R1 is configured via systemd-networkd and uses the DSA 
(Distributed Switch Architecture) with b53 switch. No visible difference 
in interfaces, vlan config, bridge config, etc. Looks like actual 
configuration in the switch in the hardware is broken.

# OK: Last good known version (booting that version is also ok)
Linux bpi 5.5.18-200.fc31.armv7hl #1 SMP Fri Apr 17 17:25:00 UTC 2020 
armv7l armv7l armv7l GNU/Linux

# NOK: no network
Linux bpi 5.6.8-200.fc31.armv7hl #1 SMP Wed Apr 29 19:05:06 UTC 2020 
armv7l armv7l armv7l GNU/Linux

# NOK: no network
Linux bpi 5.6.0-300.fc32.armv7hl #1 SMP Mon Mar 30 16:37:50 UTC 2020 
armv7l armv7l armv7l GNU/Linux

# NOK: no network
Linux bpi 5.6.19-200.fc31.armv7hl #1 SMP Wed Jun 17 17:10:22 UTC 2020 
armv7l armv7l armv7l GNU/Linux

# NOK: no network
Linux bpi 5.7.4-200.fc32.armv7hl #1 SMP Fri Jun 19 00:52:22 UTC 2020 
armv7l armv7l armv7l GNU/Linux


Saw that there were a lot of changes in the near past in the b53 driver:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/drivers/net/dsa/b53?h=v5.8-rc1+


Any ideas?

Thnx.

Ciao,
Gerhard