How to debug lots of wlp2s0: CTRL-EVENT-SIGNAL-CHANGE messages on journalct?

Hello, when I type journalctl -e it displays lots of messages similar to:
dez 20 13:43:47 n wpa_supplicant[961]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-41 noise=-95 txrate=72200

How can I debug what’s causing this?

I have an Acer Aspire E5-574 laptop with Fedora 37 installed.

uname -a output:
Linux n 6.0.13-300.fc37.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Dec 14 16:15:19 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Maybe you could post a segment of those errors as preformatted text </> so we could see the full listing.

The message seems to indicate a signal change and maybe there is a severely fluctuating signal level involved. This could be a result of the router/AP or interference on the same wirfi band or the machine itself.

Sometimes such errors can be fixed by simply doing a full power cycle of the router so the connection is newly established and may be on a different channel.

Sorry about the delay, I expected an email notification but none came. There are a lot of similar messages (I’d guess >90% of journalctl -e output).

jan 03 20:33:36 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-54 noise=-95 txrate=1000
jan 03 20:33:40 n systemd[1524]: Started app-gnome-org.gnome.Terminal-4760.scope - Application launched by gnome-shell.
jan 03 20:33:41 n systemd[1524]: Starting gnome-terminal-server.service - GNOME Terminal Server...
jan 03 20:33:41 n systemd[1524]: Started gnome-terminal-server.service - GNOME Terminal Server.
jan 03 20:33:41 n systemd[1524]: Started vte-spawn-f6e400e9-41e6-4c47-b4c4-a6431dd05244.scope - VTE child process 4785 launched by gnome-terminal-server process 47>
jan 03 20:33:50 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-76 noise=-95 txrate=72200
jan 03 20:33:52 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-58 noise=-95 txrate=1000
jan 03 20:33:52 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-58 noise=-95 txrate=1000
jan 03 20:33:54 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-52 noise=-95 txrate=58500
jan 03 20:34:00 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-78 noise=-95 txrate=65000
jan 03 20:34:02 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-59 noise=-95 txrate=1000
jan 03 20:34:02 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-59 noise=-95 txrate=1000
jan 03 20:34:08 n firefox[2643]: Unable to load split_v from the cursor theme
jan 03 20:34:10 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-78 noise=-95 txrate=72200
jan 03 20:34:12 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-51 noise=-95 txrate=1000
jan 03 20:34:16 n wpa_supplicant[901]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-59 noise=-95 txrate=72200

A web search for this message will get to threads from other distributions.

Debian bug 777170, which found a solution at Ubuntu Forums which has a moderator who is very good at sorting these issues. Note that the Ubuntu analysis used syslog, while with Fedora the messages should be in journalctl.

These are debug messages and on their own aren’t concerning, but things like microwaves, bluetooth devices, baby monitors, and neighbors can all impact the radio signal and quality of your wifi network. These messages are just letting you known that the signal connection has changed in some way. If you’re not seeing any degradation in network performance, then it’s safe to ignore them, but if you are, they are a helpful clue that you might need to look into what radio signals might be interfering with your wifi. I’ve also seen this with routers or wifi interfaces that are overheating or have faulty firmware, so maybe it’s good time to make sure your router firmware is up to date.

I’ve been experiencing spotty wi-fi connections for some months now. Tried disabling bluetooth and there are a LOT less messages, with only two short outbursts of about 8 messages in the past 10 minutes. I haven’t tested wi-fi connectivity, though.

Strangely, I don’t remember having this huge amount of messages before. But I’ll also take a look at the Forum post and Debug, thanks!

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I know that for some the connectivity with wifi has been isolated down to an older router, older router firmware, and occasionally just rebooting the the router. Just a thought.

Some wifi cards these days have bluetooth and wifi on the same chip as a cost savings, which can cause cross-interference. This is especially true for current Realtek wifi chips that have a mix of this problem with shoddy drivers. Bluetooth (and a whole bunch of other things) are also more likely to interfere with 2.4GHz than 5GHz wifi networks, so use 5GHz channels if you can as well.

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It should also be noted that USB3 can cause RF interference on 2.4 GHz:
Intel White Paper: USB 3.0* Radio Frequency Interference Impact on 2.4 GHz Wireless Devices

Is there any place where I can check if my wifi card is one of those? It doesn’t support 5G wifi. I’m not sure disabling the bluetooth was the solution anymore, because the messages were back again today (though I’m on a different house).

This is from lspci

02:00.0 Network controller: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter (rev 01)

I don’t know if this might be related or not, but sometime ago, a kernel regression “disabled” my wifi (2067108 – ath9k WiFi problem >5.16.14).

I’ve read it, since Fedora doesn’t use iwconfig, I followed linux - How to turn off Wireless power management permanently - Unix & Linux Stack Exchange, but it didn’t work.

I don’t have access to the router to try the other provided solution, though (shared dorm).

Businesses are moving to wifi 6 because it lets them have more clients in limited space. In conjested sites (apartment buildings, dorms, cubicle farms) 2.4 GHz is nearly useless for anything but IOT devices. There are many YouTube videos explaining how to upgrade Acer Aspire wifi cards. Due to businesses swapping out cards that do 5 GHz but don’t support wifi 6 there are lots of cheap used Intel wifi cards that work well with linux. Note that the tools and anti-static gear costs more than the card,
but will last much longer than your computer.

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In that case, you’re probably going to be seeing this a lot more. 2.4GHz is busy and things like bluetooth, microwaves, and baby monitors can all interfere with it. I noticed on my own home wlan that the 2.4GHz signal strength could fluctuate when the microwave or baby monitor were in use. I recommend upgrading your router to one that supports 5GHz. As @jrom99 suggested, wifi6 is the current standard and you’ll likely see a significant improvement in the quality of your network by upgrading to it. This is a personal opinion and not a community recommendation, but I prefer ASUS routers for the hardware, longevity, and hackability of them. They might cost a little more up front, but they tend to last longer. That said, if you go with something else and have an issue with Fedora, please let us know either way.

If your wifi card doesn’t support 5GHz, they’re generally very easy and not too expensive to replace. Most are PCI-E or PCI-E half-stack these days (you’ll need to know which), but I’ve swapped out several of them personally on my laptops over the past decade or so. I definitely recommend sticking with Intel for a wifi card. If opening up your laptop is uncomfortable to you, you can always buy a USB wifi card instead.

Thanks, I think I’ll look for a technician to swap my wifi card (I don’t know how to search for the correct spare part, specially since some parts are not sold anymore by the authorized technical assistance, so I think it’ll be better with someone who know how to do it haha). Unfortunately, I can’t access or change my router (shared dorm), but I know it supports 5G as there is a wifi signal (version?) available.

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