ath9k_htc: Every 2nd packet 1000ms delayed in recent kernels

From: Michael Leun
Date: Tue Jun 19 2012 - 03:07:53 EST


Hi,

ne-wlan1@elektra:/home/ml4> ping 192.168.2.1
PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data.
64 bytes from 192.168.2.1: icmp_seq=1 ttl=64 time=2010 ms
64 bytes from 192.168.2.1: icmp_seq=2 ttl=64 time=1011 ms
64 bytes from 192.168.2.1: icmp_seq=3 ttl=64 time=11.5 ms
64 bytes from 192.168.2.1: icmp_seq=4 ttl=64 time=1.12 ms
64 bytes from 192.168.2.1: icmp_seq=5 ttl=64 time=1002 ms
64 bytes from 192.168.2.1: icmp_seq=6 ttl=64 time=3.83 ms
64 bytes from 192.168.2.1: icmp_seq=7 ttl=64 time=1003 ms
64 bytes from 192.168.2.1: icmp_seq=8 ttl=64 time=4.10 ms
64 bytes from 192.168.2.1: icmp_seq=9 ttl=64 time=1003 ms
64 bytes from 192.168.2.1: icmp_seq=10 ttl=64 time=3.95 ms
64 bytes from 192.168.2.1: icmp_seq=11 ttl=64 time=1003 ms
64 bytes from 192.168.2.1: icmp_seq=12 ttl=64 time=3.78 ms


Please note the additional delay of ~1000ms every 2nd packet. This is
Kernel 3.4.3, have seen it in 3.4.2 also. Does NOT happen in 3.3.1.

Is this Issue already known? If so, I can save the work bisecting...

Happens with two different ath9k_htc cards:

Bus 002 Device 012: ID 0846:9018 NetGear, Inc. WNDA3200 802.11abgn Wireless Adapter [Atheros AR7010+AR9280]
Bus 002 Device 004: ID 0cf3:7015 Atheros Communications, Inc. TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287]

Does NOT happen with an atk9k (mini pci express) card.

--
MfG,

Michael Leun

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