Fix rfkill issues

[b0bbywan]

Occuring way too often during tests that bluetooth or wifi end up soft blocked on pi

Seems to recall there's a way to trigger rfkill unblocking at boot

[pbattino]

Not sure if it's related but..
as much as I love the Raspberry Pi, I have to say I completely stopped using the embedded Wifi AND embedded Bluetooth at the same time. I've read it's a common problem, some even explicitly state it should be avoided tout court , the two radios are simply not capable of operating at the same time without interfering with each other . (Maybe if WIFI is configured to operate on the 5ghz band only like 802.11ac ? Is it even possible?)
I can't say if my problems stemmed from that or not, but it's perhaps worth mentioning in the docs, for people less knowledgeable in wireless standards & Raspberry Pi limitations.

[b0bbywan]

Thanks for the feedback! It surprises me a bit though, my experience hasn't been that bad 😅

On the test Pi 3B+ I encounter this issue only after a complete reinstall, maybe once in 5 reinstall, and most of the time with bluetooth, not wifi.

I often test by streaming via Wifi to a remote JBL go bluetooth speaker, and I've never met that kind of issue during those tests.

I also get this issue when I unplug or replug a bluetooth dongle on the Pi B/Pi B+.

Looks like there is support for 5GHz wifi since Raspberry Pi 4. Don't see an option in Rasperry Imager to choose 2.4 or 5 GHz wifi, so no idea about this. Surely it can be done over SSH.

[pbattino]

Officially, Raspberry Pi 3 is "2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN,"....

BUT I think the 5Ghz was quietly added AT SOME POINT, not at the very beginning of the Pi 3 lifecycle. So there are Pi 3 around that don't support it. At least this is what I remember.

It's probably one of those issues that are very inconsistent and each case is different depending on how many wifi devices and networks are around, same for BT. By personal experience with BT on a Raspberry Pi 5 was that I stopped using as it disconnected after few minutes. But I haven't tried much with other BT devices, other WIFI bands etc, let's say it's very anecdotal evidence.

[b0bbywan]

Officially, Raspberry Pi 3 is "2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN,"....

Indeed you're right about that. I have dedicated wifi networks for 2.4 GHz and 5GHz, it works when I set the 5GHz SSID in Raspberry Imager.

About the bluetooth that sometimes get soft blocked, currently odio-api wil unblock it, but the Pi need a reboot from the UI or sudo systemctl restart bluetooth.service from SSH for bluetooth to work again.

I should probably add that in the docs.