Bug 42352 (Slow_wifi_ath9k) - Slow wifi connection AR9287 with ath9k 3.x kernel (also 3.1.0-rc4)
Summary: Slow wifi connection AR9287 with ath9k 3.x kernel (also 3.1.0-rc4)
Status: CLOSED OBSOLETE
Alias: Slow_wifi_ath9k
Product: Drivers
Classification: Unclassified
Component: network-wireless (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: drivers_network-wireless@kernel-bugs.osdl.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-09-04 10:23 UTC by kuba.g4
Modified: 2012-12-03 16:11 UTC (History)
5 users (show)

See Also:
Kernel Version: 3.2.6
Subsystem:
Regression: Yes
Bisected commit-id:


Attachments
lscpi output (656 bytes, text/plain)
2011-09-04 10:25 UTC, kuba.g4
Details
3.x ping while using internet connection (7.60 KB, text/plain)
2011-09-04 10:27 UTC, kuba.g4
Details
ping to router kernel 3.0 with 3.2 wireless modules (1.87 KB, text/plain)
2012-01-22 23:23 UTC, kuba.g4
Details

Description kuba.g4 2011-09-04 10:23:40 UTC
I think there is a bug in newer kernel versions. I've compiled and tested versions from 2.6.38 to 3.1.0-rc4. I noticed that my wifi connection has slowed when stitching from 2.6.x to 3.x. When I was using 3.x ath9k module after browsing some www sites and downloading some files, pings to my home router looked like this:
64 bytes from 10.0.0.138: icmp_req=503 ttl=64 time=13575 ms
64 bytes from 10.0.0.138: icmp_req=504 ttl=64 time=12882 ms
64 bytes from 10.0.0.138: icmp_req=505 ttl=64 time=12083 ms
64 bytes from 10.0.0.138: icmp_req=506 ttl=64 time=11107 ms
64 bytes from 10.0.0.138: icmp_req=507 ttl=64 time=12078 ms
64 bytes from 10.0.0.138: icmp_req=508 ttl=64 time=11533 ms

While on 2.6.39 with the same activites:
64 bytes from 10.0.0.138: icmp_req=693 ttl=64 time=2.03 ms
64 bytes from 10.0.0.138: icmp_req=694 ttl=64 time=8.85 ms
64 bytes from 10.0.0.138: icmp_req=695 ttl=64 time=2.01 ms
64 bytes from 10.0.0.138: icmp_req=696 ttl=64 time=2.23 ms
64 bytes from 10.0.0.138: icmp_req=697 ttl=64 time=5.45 ms
64 bytes from 10.0.0.138: icmp_req=698 ttl=64 time=5.72 ms

So, as you can see, the slowness is enoughto notice it. I don't have solution to this problem, but I can provide more data if you like (just tell me what you want :) ).
Comment 1 kuba.g4 2011-09-04 10:25:11 UTC
Created attachment 71662 [details]
lscpi output
Comment 2 kuba.g4 2011-09-04 10:27:29 UTC
Created attachment 71672 [details]
3.x ping while using internet connection
Comment 3 kuba.g4 2011-09-07 16:43:16 UTC
I've done some further reaserch and it seems that 2.6.38 and 2.6.39 are also broken. The last fully working kernel for my ar9287 is 2.6.37.6
Comment 4 John W. Linville 2012-01-13 19:01:21 UTC
Can you replicate this issue with a 3.2 or later kernel?
Comment 5 palothes 2012-01-15 21:08:19 UTC
Same problem here.

Kernel: 3.0.0-13-generic (also happened with 2.6.x)

lspci:
02:00.0 Network controller: Atheros Communications Inc. AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
Comment 6 kuba.g4 2012-01-22 23:23:52 UTC
Created attachment 72151 [details]
ping to router kernel 3.0 with 3.2 wireless modules
Comment 7 kuba.g4 2012-01-22 23:29:18 UTC
Yes I can replicate this issue. My wifi connection also has slowed when I switched from 2.6.37.6 to 3.0.17 with 3.2 wifi modules. I can attach more data if you want :)
Comment 8 Garri 2012-02-19 09:18:34 UTC
I can confirm that issue even in 3.2.6. Problem exists since 2.6.38. So far I am using 2.6.37.6, as it works well. I often use ssh/telnet connections to remote and local hosts, so the difference is obvious for me (as terminal lags periodically).

lspci -k:
03:00.0 Network controller: Atheros Communications Inc. AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
	Subsystem: Foxconn International, Inc. Device e034
	Kernel driver in use: ath9k
	Kernel modules: ath9k


Output statistics pinging local router is same room (excellent signal strength), running 2.6.37.6 kernel:
--- 192.168.1.1 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 99183ms
rtt min/avg/max/mdev = 1.787/2.958/86.539/8.559 ms


Output statistics pinging local router is same room (excellent signal strength), running 3.2.6 kernel:
--- 192.168.1.1 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 99152ms
rtt min/avg/max/mdev = 1.784/24.577/143.923/27.575 ms


Average RTT increased to 24 ms in second output.
Comment 9 Garri 2012-12-02 20:18:52 UTC
Yesterday I updated kernel 2.6.37.6 to 3.6.8. Problem solved for me! Thanks.

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