wpa_supplicant: Help chasing down regular WiFi disconnects on Raspberry Pi?

bls s bls3427 at outlook.com
Fri Apr 19 05:59:47 PDT 2019


Jouni, thank you for your insights on this. Greatly appreciated. 

> On Apr 7, 2019, at 6:30 AM, Jouni Malinen <j at w1.fi> wrote:
> 
>> On Thu, Mar 21, 2019 at 07:15:33PM +0000, bls s wrote:
>> On affected systems, carrier drops at semi-regular intervals (approximately every 5 1/2 to 6 minutes, but sometimes more frequently). The message in the wpa_supplicant debug log is "wlan0 ....Remove id... 'SSID' due to wpa_bss_flush_by_age" (see logs below)
> 
> That message is not of relevance for the issue, i.e., it is expected
> behavior. All that there is about disconnection is this:
> 
> RTM_NEWLINK: ifi_index=3 ifname=wlan0 operstate=2 linkmode=1 ifi_family=0 ifi_flags=0x1003 ([UP])
> nl80211: Event message available
> nl80211: Ignored event (cmd=48) for foreign interface (ifindex 3 wdev 0x0)
> nl80211: Drv Event 48 (NL80211_CMD_DISCONNECT) received for wlan0
> nl80211: Disconnect event
> wlan0: Event DEAUTH (12) received
> wlan0: Deauthentication notification
> wlan0:  * reason 0 (locally generated)
> Deauthentication frame IE(s) - hexdump(len=0): [NULL]
> wlan0: CTRL-EVENT-DISCONNECTED bssid=4c:01:43:69:21:16 reason=0 locally_generated=1
> 
> In other words, the kernel driver is indicating that the association has
> been lost. This does not look like anything that would be caused by
> wpa_supplicant.
> 
>> When I first started looking into this, I found that the Pixel desktop (specifically, lxpanel) does wpa_cli SCANs every minute. So, I made a script (wpaping) that does a 'wpa_cli -i wlan0 scan' every 2 minutes, and the disconnects stopped. Most of the time, but not always, so still hunting for the root cause.
> 
> I'd guess this periodic scan operation keeps the driver active and not
> losing some state or synchronization with the AP.
> 
>> Again, not thinking that this is a wpa_supplicant issue. I suppose this could be a brcm wireless driver issue, or some issue with a bunch of different Access Points. If it is, hoping that there's a magic config setting to correct it ;)
> 
> Looks like a driver issue to me.. Either the local driver somehow loses
> the connection, e.g., due to not seeing Beacon frames from the AP or
> thinking the connection is idle and not used, etc.; or the AP
> disconnects the station for some reason (though, in that case the
> locally_generated=1 flag should not be there).
> 
>> Thanks in advance for any guidance, suggestions, and/or condolences.
> 
> The best next step would be to debug the driver to see why it reports
> disconnection in about 5.3-6 minutes from association.
> 
> -- 
> Jouni Malinen                                            PGP id EFC895FA



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