WiFi region always "world" even when specified otherwise in wpa_supplicant.conf

[coolbho3k]

The WiFi region on MiSTer seems to always be "world", even if it's set to TW or US or anything else in wpa_supplicant.conf.

As a result, I can't see my 5 GHz access point when it's set to certain US-specific channels, even when wpa_supplicant.conf is set to US. Being set to world may also limit the transmit power of the USB dongle, but this is a less critical issue.

Talking with @birdybro in the channel, we think that we need CRDA to be able to set the WiFi region correctly. Can we add it?

My adapter is a Asus AC-53 Nano (RTL8812BU), but from what I understand this doesn't matter.

Symptoms:

• Run iw reg get on any MiSTer and you get this:

# iw reg get
global
country 00: DFS-UNSET

• As a result the region being set to world, MiSTer won't ever see or connect to APs on certain region-specific channels even if wpa_supplicant.conf is configured correctly.

[sorgelig]

i've tried to add crda which didn't fix the issue. iw reg set US doesn't change the region. What i've read is that region is handled by kernel itself. It reads /lib/firmware/regulatory.db and then should handle it somehow. I have no idea how it works, so if you know more then you can tinker with kernel config to find a working solution.

[coolbho3k]

Thanks, I'll keep poking. Firmware is definitely there.

[coolbho3k]

I think I may have narrowed it down to the fact that cfg80211 was trying to load regulatory.db prior to the rootfs being mounted, similar to the problem this person was facing: https://unix.stackexchange.com/questions/513449/unable-to-load-regulatory-database

Their solution was to build cfg80211 as a module.

So the reason I think this is that I get this log in dmesg:
regulatory.0: direct firmware load for regulatory.db failed with error -2

Prior to seeing messages about the rootfs being mounted.

[sorgelig]

ok. i will try it as a module. probably tomorrow

[coolbho3k]

Thanks. @amstan and I have also been hacking at it so will let you know if we get to it first.

[sorgelig]

yes, i can set region now. Although i'm not sure how to test it. I will post test version here later.

[sorgelig]

try this test build of linux+kernel:
https://mega.nz/file/MQIgXbSZ#5ycVQd8XvMn-hUYtMV30wRwv62JqxHdHNNkqJaBv8ic

[coolbho3k]

I'll try this tonight. My way of trying it is to set my router's channel to 100 and just see if the MiSTer can find the SSID before and after.

[coolbho3k]

I think it's still worth keeping CONFIG_CFG80211=m. That's definitely better as iw reg set now works, and the kernel is now respecting the region set in wpa_supplicant.conf too.

It actually doesn't work for me - I can't scan channel 52 or 100. But I suspect my problem now might be specific to Realtek chipsets. I've read we might need to set CONFIG_RTW_IOCTL_SET_COUNTRY=y for Realtek.

This is a rabbit hole. If you don't have the adapter or the time, I can keep debugging as well.