Comment 36 for bug 837076

Still happening with the latest kernel (3.11.0-8):

[hloeung@darkon tmp]$ uname -a
Linux darkon 3.11.0-8-generic #15-Ubuntu SMP Fri Sep 20 04:11:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

[hloeung@darkon tmp]$ iwconfig
lo no wireless extensions.

Module was only loaded with 802.11n enabled and within a few minutes, over 1.7k TX retries:

wlan0 IEEE 802.11abgn ESSID:"star-local-5GHz"
          Mode:Managed Frequency:5.22 GHz Access Point: C0:25:06:A6:31:0E
          Bit Rate=162 Mb/s Tx-Power=15 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Power Management:on
          Link Quality=58/70 Signal level=-52 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:1714 Invalid misc:2 Missed beacon:0

Also spikes in latency and packet loss:

64 bytes from 203.12.160.35: icmp_seq=12 ttl=227 time=82.6 ms
64 bytes from 203.12.160.35: icmp_seq=13 ttl=227 time=108 ms
64 bytes from 203.12.160.35: icmp_seq=14 ttl=227 time=25.0 ms
64 bytes from 203.12.160.35: icmp_seq=15 ttl=227 time=22.0 ms
64 bytes from 203.12.160.35: icmp_seq=16 ttl=227 time=49.5 ms
64 bytes from 203.12.160.35: icmp_seq=17 ttl=227 time=53.0 ms
64 bytes from 203.12.160.35: icmp_seq=18 ttl=227 time=25.8 ms
64 bytes from 203.12.160.35: icmp_seq=20 ttl=227 time=650 ms
64 bytes from 203.12.160.35: icmp_seq=21 ttl=227 time=1806 ms
64 bytes from 203.12.160.35: icmp_seq=22 ttl=227 time=813 ms
64 bytes from 203.12.160.35: icmp_seq=23 ttl=227 time=41.3 ms
64 bytes from 203.12.160.35: icmp_seq=24 ttl=227 time=42.1 ms
64 bytes from 203.12.160.35: icmp_seq=25 ttl=227 time=40.3 ms
64 bytes from 203.12.160.35: icmp_seq=26 ttl=227 time=57.3 ms
64 bytes from 203.12.160.35: icmp_seq=27 ttl=227 time=47.3 ms
64 bytes from 203.12.160.35: icmp_seq=28 ttl=227 time=20.0 ms
64 bytes from 203.12.160.35: icmp_seq=29 ttl=227 time=53.2 ms
64 bytes from 203.12.160.35: icmp_seq=30 ttl=227 time=42.4 ms
64 bytes from 203.12.160.35: icmp_seq=31 ttl=227 time=36.3 ms
64 bytes from 203.12.160.35: icmp_seq=32 ttl=227 time=55.4 ms
64 bytes from 203.12.160.35: icmp_seq=33 ttl=227 time=44.2 ms
64 bytes from 203.12.160.35: icmp_seq=34 ttl=227 time=1510 ms
64 bytes from 203.12.160.35: icmp_seq=35 ttl=227 time=501 ms
64 bytes from 203.12.160.35: icmp_seq=36 ttl=227 time=1290 ms
64 bytes from 203.12.160.35: icmp_seq=37 ttl=227 time=288 ms
64 bytes from 203.12.160.35: icmp_seq=38 ttl=227 time=55.3 ms
64 bytes from 203.12.160.35: icmp_seq=39 ttl=227 time=37.0 ms

Yet with 802.11n disabled, all seems happier.