GeorgeIoak
Posts: 46
Joined: Thu Aug 30, 2012 1:50 am

Odd WiFi Drop Out Issues

Thu Sep 12, 2019 7:28 pm

I have a Raspbeery Pi Model 3+ which is connected to the official 7" touch screen and an OpenSprinkler board. I am using the built-in WiFi and I can access the Pi through ssh but after anywhere from 1 to maybe 5 days I cannot ssh into the Pi. When I go to the screen and check Network Manager in the menu it shows the 5G symbol, full strength, and the SSID name.

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[email protected]:~ $ cat /proc/device-tree/model
Raspberry Pi 3 Model B Plus Rev 1.3

[email protected]:~ $ uname -a
Linux OSPI 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux

[email protected]:~ $ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 9 (stretch)"
NAME="Raspbian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

[email protected]:~ $ sudo iw dev wlan0 info
Interface wlan0
        ifindex 3
        wdev 0x1
        addr b8:27:eb:22:cd:c0
        ssid TheIoaks
        type managed
        wiphy 0
        channel 48 (5240 MHz), width: 80 MHz, center1: 5210 MHz
        txpower 31.00 dBm
If I check the logs I see a lot of this if I cannot ssh into the Pi:

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[email protected]:~ $ dmesg | grep error
[67604.358261] brcmfmac: brcmf_run_escan: error (-110)
[67604.358271] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67664.358325] brcmfmac: brcmf_run_escan: error (-110)
[67664.358335] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67724.438442] brcmfmac: brcmf_run_escan: error (-110)
[67724.438452] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67784.438503] brcmfmac: brcmf_run_escan: error (-110)
[67784.438513] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67844.438621] brcmfmac: brcmf_run_escan: error (-110)
[67844.438632] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67904.438768] brcmfmac: brcmf_run_escan: error (-110)
[67904.438778] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[67964.438898] brcmfmac: brcmf_run_escan: error (-110)
[67964.438908] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[68024.439042] brcmfmac: brcmf_run_escan: error (-110)
[68024.439052] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[68084.439206] brcmfmac: brcmf_run_escan: error (-110)
[68084.439216] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[68144.439380] brcmfmac: brcmf_run_escan: error (-110)
[68144.439390] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
[68204.439588] brcmfmac: brcmf_run_escan: error (-110)
[68204.439599] brcmfmac: brcmf_cfg80211_scan: scan error (-110)
When I can ssh into the Pi I find this:

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[email protected]:~ $ journalctl | grep carrier
Sep 11 08:01:12 OSPI dhcpcd[370]: eth0: waiting for carrier
Sep 11 08:01:12 OSPI dhcpcd[370]: wlan0: waiting for carrier
Sep 11 08:01:12 OSPI dhcpcd[370]: wlan0: carrier acquired
Sep 11 08:01:12 OSPI dhcpcd[370]: wlan0: carrier lost
Sep 11 08:01:21 OSPI dhcpcd[370]: wlan0: carrier acquired
Sep 11 08:01:38 OSPI dhcpcd[370]: wlan0: carrier lost
Sep 11 08:01:59 OSPI dhcpcd[370]: wlan0: carrier acquired
Sep 11 08:04:27 OSPI dhcpcd[370]: wlan0: carrier lost
Sep 11 08:04:28 OSPI dhcpcd[370]: wlan0: carrier acquired
Sep 12 01:59:49 OSPI dhcpcd[370]: wlan0: carrier lost
Sep 12 01:59:52 OSPI dhcpcd[370]: wlan0: carrier acquired
Sep 12 01:59:56 OSPI dhcpcd[370]: wlan0: carrier lost
Sep 12 01:59:57 OSPI dhcpcd[370]: wlan0: carrier acquired
I have several other devices and computers that connect through WiFi and I don't seem to have a problem with them. If there is a problem they are all able to self recover (iPad, Mac, Windows PC, Android phone, Smart Devices). Because of that fact I don't think it's an issue with the router. This has been going on for a long time so it's not related to a new update. I've been searching trying to find solutions but so far I can't and I'm not sure what else I can do to try and debug this.

When this happens I haven't been able to recover the WiFi other than just rebooting the Pi.

Any help in trying to narrow down what is going on and how to fix it would be appreciated!

Andyroo
Posts: 4134
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Odd WiFi Drop Out Issues

Thu Sep 12, 2019 7:45 pm

Possibly power supply issues?

I had a real problem till I moved to an official power supply.

You could try

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sudo iw wlan0 set power_save off
but I think that would be hitting you before this time.

Also this thread may help https://www.raspberrypi.org/forums/view ... p?t=239730
Need Pi spray - these things are breeding in my house...

GeorgeIoak
Posts: 46
Joined: Thu Aug 30, 2012 1:50 am

Re: Odd WiFi Drop Out Issues

Thu Sep 12, 2019 10:47 pm

I don't think that this is related to power supply, it's got a known good power supply rated at 2.4A and measured voltage at the Pi is 5.1V

I've read multiple threads that the default power settings for WiFi are OFF and that when you display the settings there is a bug that shows that power savings are turned on. At one point I did try adding it to the config file and I still got this problem.

I've looked at that thread and I was hoping to find the root cause of why this is happening rather than just resetting the Pi or WiFi on a periodic basis. Of course if I can't find a solution I can use that method but if I remember correctly I've tried to bring the WiFi down and then up when this happens (working from the LCD connected to the Pi) and that didn't revive the connection so right now the only thing that works is rebooting the Pi.

Are there other logs or settings that I can enable to see what is causing this?

epoch1970
Posts: 3538
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: Odd WiFi Drop Out Issues

Fri Sep 13, 2019 8:04 am

You can try killing the wpa_supplicant process if it survives your network down/up maneuver.
Power source stability is a possible cause indeed.
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

GeorgeIoak
Posts: 46
Joined: Thu Aug 30, 2012 1:50 am

Re: Odd WiFi Drop Out Issues

Fri Sep 13, 2019 3:36 pm

Next time the connection drops I'll try

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service wpa_supplicant stop
and then see if I can start the service again and gain access again.

If it was a power supply issue wouldn't I expect to see other "random" errors in the logs?

Andyroo
Posts: 4134
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Odd WiFi Drop Out Issues

Fri Sep 13, 2019 4:06 pm

I did not on my 3 - WiFi was the only thing that gave me issues.

No idea why the WiFi was impacted but I know when I changed to power over then the issues cleared. No change of software at OS or application level and no relocation of Pi or AP :roll: :?: :roll:
Need Pi spray - these things are breeding in my house...

vamfoom
Posts: 1
Joined: Fri Sep 13, 2019 10:07 pm

Re: Odd WiFi Drop Out Issues

Fri Sep 13, 2019 10:16 pm

I have 4 Raspberry Pis (three 3 B+ and a Zero W), they all seem to have issues with wifi. They all utilize genuine Raspberry Pi power supplies. I've scoured the whole Internet and found a lot of people having similar issues with suggestions to fix/work-around the issue. I've disable power management using all the methods mentioned but nothing really seems to help. The only thing that really helps a little is a script that monitors connectivity to an IP to detect network drops then restart the wifi interface, but even this is getting to be a bit unreliable. At this point, i wouldn't consider using the Pi with Wifi. Using the LAN port is the only good solution to network issue on the Pi. Shouldn't the default for Raspbian be set to make this reliable, if there is really a solution?

I'm keeping a log and on the pi zero, there could be periods of up to 10 minute of wifi issues:

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09-13 02:20:01 PM Network is UP. Just exit the program.
09-13 02:21:01 PM Network is UP. Just exit the program.
09-13 02:22:01 PM Network is UP. Just exit the program.
09-13 02:23:01 PM Network is UP. Just exit the program.
09-13 02:24:02 PM Network is UP. Just exit the program.
09-13 02:25:01 PM Network is DOWN. Perform a reset
09-13 02:26:02 PM Network is DOWN. Perform a reset
09-13 02:27:01 PM Network is DOWN. Perform a reset
09-13 02:28:01 PM Network is DOWN. Perform a reset
09-13 02:29:02 PM Network is DOWN. Perform a reset
09-13 02:30:02 PM Network is DOWN. Perform a reset
09-13 02:31:01 PM Network is DOWN. Perform a reset
09-13 02:32:01 PM Network is DOWN. Perform a reset
09-13 02:33:02 PM Network is DOWN. Perform a reset
09-13 02:34:01 PM Network is DOWN. Perform a reset
09-13 02:35:01 PM Network is DOWN. Perform a reset
09-13 02:36:01 PM Network is DOWN. Perform a reset
09-13 02:37:01 PM Network is DOWN. Perform a reset
09-13 02:38:02 PM Network is UP. Just exit the program.
09-13 02:39:01 PM Network is UP. Just exit the program.
09-13 02:40:01 PM Network is UP. Just exit the program.
09-13 02:41:02 PM Network is UP. Just exit the program.
09-13 02:42:01 PM Network is UP. Just exit the program.
09-13 02:43:01 PM Network is UP. Just exit the program.

epoch1970
Posts: 3538
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: Odd WiFi Drop Out Issues

Sat Sep 14, 2019 11:19 am

Well of course on the internet you will find people having issues, with WiFi or anything else.
I don’t have much issues with WiFi using Raspbian on my 3Bs, never had IIRC. I don’t feel the urge to post “it works” all over the place...

Wireless is complicated, the environment (neighbors?) can influence its performance. And AP settings/quality, client settings, as well.

In case of problems I would check the client config against the official documentation, set the AP to factory defaults, and see what happens.
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

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