RPi CM4 WiFi Roaming/Fast Transition Troubleshooting (Driver issue?)

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I’m attempting to use a Raspberry Pi CM4 SC0669 in a stadium/arena environment and am having difficulty getting the Pi to properly handle roaming across different WiFi APs in that setting. The CM4 is running standard balenaOS. I have a few questions about the hardware, firmware, etc. as I’m working through some troubleshooting.

  • I looked through dmesg to figure out what’s going on with the drivers. The BCM43455 driver seems to be failing to load, at which point the BCM4345/6 driver is used instead. What are these two drivers, and is this behavior indicative of some problem? Or am I misinterpreting dmesg?
  • When running lshw, the CM4 reports that a device with vendor id Broadcom and product id 43430 is connected to the SDIO. My understanding was that the CM4 used the BCM43455, not the 43430. Why does this show up in lshw?
  • Does the CM4 support fast roaming, and does it support 802.11/k/v/r? Is there any reason the CM4 would be expected to have difficulties with roaming in a stadium/arena environment?

For what it’s worth, I see almost identical outputs with the Pi4B, aside from slight variation in the dmesg error line.

Let me know if there is any other information I can provide, I can send full outputs for lshw, dmesg, etc. if needed. Thank you!

Snips for reference

lshw:

capabilities: sdio
*-interface:0
description: Wireless interface
product: 43430
vendor: Broadcom

Dmesg:

brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.raspberrypi,4-compute-module.bin failed with error -2
...
brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/6 wl0: Nov 1 2021 00:37:25 version 7.45.241 (1a2f2fa CY) FWID 01-703fd60

Firmware files:

ls /lib/firmware/brcm/
BCM43430A1.hcd                                  brcmfmac43430-sdio.txt
BCM4345C0.hcd                                   brcmfmac43455-sdio.bin
brcmfmac43143-sdio.bin.xz                       brcmfmac43455-sdio.clm_blob
brcmfmac43143.bin.xz                            brcmfmac43455-sdio.raspberrypi,3-model-a-plus.txt
brcmfmac43430-sdio.bin                          brcmfmac43455-sdio.raspberrypi,3-model-b-plus.txt
brcmfmac43430-sdio.clm_blob                     brcmfmac43455-sdio.raspberrypi,4-compute-module.txt
brcmfmac43430-sdio.raspberrypi,3-model-b.txt    brcmfmac43455-sdio.raspberrypi,4-model-b.txt
brcmfmac43430-sdio.raspberrypi,model-zero-w.txt brcmfmac43455-sdio.txt

ls /lib/firmware/cypress/
cyfmac43430-sdio.bin         cyfmac43430-sdio.clm_blob
cyfmac43455-sdio-minimal.bin cyfmac43455-sdio.bin cyfmac43455-sdio.clm_blob
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