[Cerowrt-devel] Bug 442?

[Sebastian Moeller]

Hi List, hi Dave,

I just had a case of devices on the 2.4GHz radio not connecting anymore (the 5GHz radio still worked).

This output was stable while the devices failed to obtain IP addresses:
root at nacktmulle:/usr/lib/CeroWrtScripts# cat /sys/kernel/debug/ieee80211/phy0/ath9k/queues
\(VO):  qnum: 0 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(VI):  qnum: 1 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(BE):  qnum: 2 qdepth:  0 ampdu-depth:  0 pending:  13 stopped: 1
(BK):  qnum: 3 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(CAB): qnum: 8 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0

Note one of the devices was connected to the same radio before and got somehow forced to reconnect and failed to actually do so…

Here is what I saw from log read:

Sun Jul 13 19:15:08 2014 daemon.info hostapd: sw00: STA 10:68:3f:4b:0b:48 IEEE 802.11: authenticated
Sun Jul 13 19:15:08 2014 daemon.info hostapd: sw00: STA 10:68:3f:4b:0b:48 IEEE 802.11: associated (aid 2)
Sun Jul 13 19:15:08 2014 daemon.info hostapd: sw00: STA 10:68:3f:4b:0b:48 WPA: pairwise key handshake completed (RSN)
Sun Jul 13 19:15:08 2014 daemon.info dnsmasq-dhcp[2809]: DHCPREQUEST(sw00) 192.168.2.107 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:08 2014 daemon.info dnsmasq-dhcp[2809]: DHCPNAK(sw00) 192.168.2.107 10:68:3f:4b:0b:48 wrong address
Sun Jul 13 19:15:11 2014 daemon.info dnsmasq-dhcp[2809]: DHCPREQUEST(sw00) 192.168.2.107 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:11 2014 daemon.info dnsmasq-dhcp[2809]: DHCPNAK(sw00) 192.168.2.107 10:68:3f:4b:0b:48 wrong address
Sun Jul 13 19:15:13 2014 daemon.info dnsmasq-dhcp[2809]: DHCPDISCOVER(sw00) 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:13 2014 daemon.info dnsmasq-dhcp[2809]: DHCPOFFER(sw00) 172.30.42.90 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:17 2014 daemon.info dnsmasq-dhcp[2809]: DHCPDISCOVER(sw00) 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:17 2014 daemon.info dnsmasq-dhcp[2809]: DHCPOFFER(sw00) 172.30.42.90 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:26 2014 daemon.info dnsmasq-dhcp[2809]: DHCPDISCOVER(sw00) 10:68:3f:4b:0b:48 
Sun Jul 13 19:15:26 2014 daemon.info dnsmasq-dhcp[2809]: DHCPOFFER(sw00) 172.30.42.90 10:68:3f:4b:0b:48 


	I reconnected the 2.4GHz radio from https://gw.home.lan:81/cgi-bin/luci/;stok=64f33ba722ed8a68b13ad5644e60629b/admin/network/network (by hitting the connect button for sw00)

Now I see:

root at nacktmulle:/usr/lib/CeroWrtScripts# cat /sys/kernel/debug/ieee80211/phy0/ath9k/queues
(VO):  qnum: 0 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(VI):  qnum: 1 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(BE):  qnum: 2 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(BK):  qnum: 3 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0
(CAB): qnum: 8 qdepth:  0 ampdu-depth:  0 pending:   0 stopped: 0

So this seems to be “fixed” without having to reboot cerowrt. So we might consider working aroung this bug by checking  /sys/kernel/debug/ieee80211/phy0/ath9k/queues repeatedly and reconnecting the 2.4GHz radio if the queue seems stopped? Now I would like to know whether this actually is bug 442 (I seem to recall that other afflicted users needed to reboot cerowrt to get the radio back, or did they simply not try to just get sw00 unstuck in a less drastic manner? And/or maybe the re-connect only fixes some symptoms and the router will wedge layer on for good?) I attached the output of cerostats.sh just in case someone has an idea what to try next...

Best Regards
	Sebastian


-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: cerostats_output.txt
URL: <https://lists.bufferbloat.net/pipermail/cerowrt-devel/attachments/20140713/aff17b05/attachment-0002.txt>