Problems with getting BananaPi PBi-R4 to work with AsiaRF AW7915-NP1

Installing and Using OpenWrt Network and Wireless Configuration
1

I am writing to ask for help with the BananaPi BPI-R4 with OpenWRT.

The device is not officially supported yet, but I can nevertheless build for this device using the OpenWRT master branch.

I have numerous problems with getting BananaPi PBi-R4 to work with AsiaRF AW7915-NP1. I have the impression that the BananaPi works OK, and the problems are with the WiFi card.

After many days of unsuccessfully trying to get the setup working with Wifi-roaming, I re-flashed both routers into a minimal example below.

What I did:

  1. I got hold of two BananaPi-R4 with one AsiaRF AW7915-NP1 each.
    photo_2024-10-20_19-44-14|375x500](l8yKJYFc2APUIXSreCwXwI5yLau.jpeg)
    [photo_2024-10-20_19-43-58|375x500(qOz2jCKsLLinp6D6GOa4KsnDMH0.jpeg)
  2. I Assemblied the BananaPi-R4 with theAsiaRF AW7915-NP1 and then put them into the case.
    photo_2024-10-20_19-44-17
    photo_2024-10-20_19-44-17960×1280 141 KB
  3. I built the current version of the OpenWRT firmware. I had to use master, as BananaPi-R4 are not supported yet. My last commit is from Thu Oct 17 20:33:36, 3c76bed6a9.
  4. I enabled the following items:
    a) BananaPi BPi-R4 (basic one, not the Bananapi BPi-R4 2.5GE).
    b) MT7915E and MT791 Firmware
    c) LuCI
  5. Flashed the firmware to both routers.
  6. Factory-reset each router.
  7. I connected one router to the WAN ethernet. That network uses its own DHCP server, so the configuration is plug & play. Let's call this router "Main".
  8. I connected both routers together with a long ethernet cable, putting the cable into one of the "LAN" ports.
  9. I turned on Radio on both routers. They automatically have chosen a 80Ghz-wide band of 802.11ax in channel 36. I set up a same WPA2-PSK password for both routers.
    openwrt_enable_wifi|690x261(d4ers0JMdODCjkjn1Li6YQMXQns.png)
  10. I've changed the default LAN segment from 192.168.1.0/24 to 192.168.10.0/24 to avoid any interference with the upstream WAN (which also happens to be on the 192.168.1.x network).
  11. On the Aux router I've disabled the DHCP server.
    openwrt_slave2|690x365
  12. I've turned on the 802.11r roaming on both routers. Just a
    2024-10-26_15-07 - openwrt-roaming|294x500(kf6EQ1B1J94Cs64c0p4yrYVi3YY.png)

Here are the relevant configuration screens of the Main router:
MAC Address: 42:AE:8C:F1:AA:0E
IP Address: 192.168.10.90
DHCP Server: yes
openwrt_master5|417x500(7CzrrAOdS3gtC9WcpEsHswNbLJE.png)
openwrt_master4|690x362(y8Nje1PXwin0aK9sPNz4lMi5KBP.png)
openwrt_master3|669x500(jhayjw8sBeSeaW63E6T7qs0WWsJ.png)
openwrt_master2|655x500(5dHCGUxAtAbMyYYzdA2avNEGcGV.png)
openwrt_master1|531x499(oUDzSVn0iqe6gQOgzzeDSyqL5Ts.png)

Here are the relevant configuration screens from the Aux router:
Mac Address: 42:AE:8C:F1:AA:0E
IP Address: 192.168.10.89
DHCP Server: no
openwrt_slave3|690x361(9V1TXslSjUXbnogkhfAkZP8wAOL.png)
openwrt_slave2|690x365(nFGGJOde8ebOQMeFR1vpT72dAOB.png)
openwrt_slave1|677x500(iyCQDGju9RpgVVR5vwuikXCIFh.png)

The roaming transition from Aux to Main works great. The downtime is about 500ms or less.

The roaming transition back from Main to Aux is the real problem. What happens looks as if either side banned the other one, and I fail to connect back for at least a minute.

Here's the screen recording of my debugging session, where I walked between the rooms to trigger the roaming transition.

Edit: Because I am a new user, I cannot post the link directly. Sorry for the inconvenience

https asciinema at org/a/VGcujHGMbDeszgajSlq7SYmMi

Sorry for the bad links with my images - I don't have permission to upload more than 1 picture per post.