Scan only shows 1 ssid some of the time

[baileysage]

Running on a raspi3 B v1.2 on Buster. Not using wpa.

Sometimes scan will only return one ssid, even if all of the available networks show up in iwlist just before launching.

We ARE setting a network priority on the ssid that always shows up, but otherwise running according to the README.

[marclennox]

I get this also.

[majorz]

That's interesting. What happens if you run nmcli d wifi rescan just before running wifi-connect? iwlist uses the older wireless extensions for Linux where NetworkManager is talking to the kernel through the newer netlink mechanism (the iw utility uses that as well). iw dev wlan0 scan is also an interesting output.

[marclennox]

I will test this out and let you know.

[baileysage]

We get the same single network from nmcli d wifi rescan that we see in wifi-connect.

Interestingly, running sudo iw wlan0 scan will kick something into gear and then nmcli and wifi-connect will see all available networks. BUT, then, connecting to the network will fail and restart the AP. Then, wifi-connect will show the network we attempted to connect to, allow us to select it, enter credentials, and connect as normal. I have sudo journalctl -fu NetworkManager output I can sanitize and share if that would be helpful.

[majorz]

Thanks for the feedback! The logs from NetworkManager would not reveal anything most probably, but I could be wrong.

There may be some kernel errors. Recently I have seen more and more instabilities with the RPi WiFi driver/firmware. Could you please also check the dmesg output and let me know if you see any crashes there.

NetworkManager delegates currently scanning to the wpa_supplicant. In the future probably that will be done by default by iwd - a new wireless daemon from Intel, which has a much cleaner codebase, better automated testing and is using more kernel routines. This one unfortunately is not compatible with the current RPi 4.19 kernel, so switching to it is not an option. The current combination of buggy drivers/firmware and wpa_supplicant issues makes things quite unstable. Other WiFi chips are even worse.

It would be best if I can reproduce this issue and I am going to do a round of testing. Are there any particular steps that you would recommend? You are probably running latest Raspbian Lite (Buster) - correct me if I am wrong. The error should also be affecting our balenaOS since we are running the same kernel and drivers (although patch versions may vary).

Also if you are running Raspbian Lite, are you running it with full system upgrade or a stock one from September?

[baileysage]

Running on Raspbian Buster, not Lite. We did a full system upgrade.

Other than avoiding Android 9 (we were having issues with the captive portal that are Android's problem, not yours) nothing specific that I can tell, though let me know if I can provide more detail. Will get the dmesg output in the morning.

[majorz]

No luck with reproducing on my side. I did a full system upgrade and tried this multiple times with power cycling or just rerunning, but the result was the same.

[baileysage]

Ok, np. What if you are already connected to a wifi network when you run wifi-connect? (Yes, I understand this is odd.)

[majorz]

@baileysage Actually now that you said this can you run both nmcli d wifi rescan and nmcli d wifi before launching WiFi Connect. I believe this should make the problem disappear for you - a workaround of some sort.

[marclennox]

Yes I will try this in the next hour or so

…

On Thu., Jan. 23, 2020, 12:51 Zahari Petkov, ***@***.***> wrote: @baileysage <https://github.com/baileysage> Actually now that you said this can you run both nmcli d wifi rescan and nmcli d wifi before launching WiFi Connect. I believe this should make the problem disappear for you - a workaround of some sort. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#327>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAE7CZBIIHYVQF6DWFLE4PTQ7HKLTANCNFSM4KG3CGHQ> .

[baileysage]

@majorz That seems to work! I'll have it tested on a couple different units and let you know if it goes differently.

[majorz]

Awesome, let's keep this open as I would like to add this to wifi-connect itself whenever we upgrade our base library to libnm-rs (the new Rust bindings for libnm).

[HughWarrington]

FYI this is a problem for us when using:

• RPi 4
• balenaOS 2.53.12+rev1
• wifi-connect release v4.3.1