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Vrong

Member

Registered: 2017-01-10

Posts: 3

Strange wifi lag peaks with TP-WN722N and ath9k_htc

Hello,

I have an issue with the TP LINK TP-WN722N usb wifi card that I can't get solved. The card most of the time works well and uses ath9k_htc module. The issue is that sometimes it becomes very laggy for a few seconds.
For example if I use the ping command to test the network continuously I get this:

[...]
64 bytes from 5.196.200.174: icmp_seq=3285 ttl=54 time=9.70 ms
64 bytes from 5.196.200.174: icmp_seq=3286 ttl=54 time=6.94 ms
64 bytes from 5.196.200.174: icmp_seq=3287 ttl=54 time=6.84 ms
64 bytes from 5.196.200.174: icmp_seq=3288 ttl=54 time=6.96 ms
64 bytes from 5.196.200.174: icmp_seq=3289 ttl=54 time=6.85 ms
64 bytes from 5.196.200.174: icmp_seq=3290 ttl=54 time=6.96 ms
64 bytes from 5.196.200.174: icmp_seq=3291 ttl=54 time=21.0 ms
64 bytes from 5.196.200.174: icmp_seq=3292 ttl=54 time=8.85 ms
64 bytes from 5.196.200.174: icmp_seq=3293 ttl=54 time=1000 ms
64 bytes from 5.196.200.174: icmp_seq=3294 ttl=54 time=1252 ms
64 bytes from 5.196.200.174: icmp_seq=3295 ttl=54 time=1045 ms
64 bytes from 5.196.200.174: icmp_seq=3296 ttl=54 time=1239 ms
64 bytes from 5.196.200.174: icmp_seq=3297 ttl=54 time=1098 ms
[...]
64 bytes from 5.196.200.174: icmp_seq=3320 ttl=54 time=1152 ms
64 bytes from 5.196.200.174: icmp_seq=3321 ttl=54 time=1004 ms
64 bytes from 5.196.200.174: icmp_seq=3322 ttl=54 time=828 ms
64 bytes from 5.196.200.174: icmp_seq=3323 ttl=54 time=620 ms
64 bytes from 5.196.200.174: icmp_seq=3324 ttl=54 time=420 ms
64 bytes from 5.196.200.174: icmp_seq=3325 ttl=54 time=212 ms
64 bytes from 5.196.200.174: icmp_seq=3326 ttl=54 time=13.1 ms
64 bytes from 5.196.200.174: icmp_seq=3327 ttl=54 time=8.99 ms
64 bytes from 5.196.200.174: icmp_seq=3328 ttl=54 time=6.82 ms
64 bytes from 5.196.200.174: icmp_seq=3329 ttl=54 time=6.96 ms
64 bytes from 5.196.200.174: icmp_seq=3330 ttl=54 time=7.71 ms
64 bytes from 5.196.200.174: icmp_seq=3331 ttl=54 time=7.46 ms

dmesg doesn't seems to get any message about this.

It might be not be noticeable to much but it's a pain in the ass when playing online games. It happens often, like every minute.

I tried multiple kernels, distros, computers. It has the same issue on every linux computer, but it works fine on Windows. It's not a poor signal strength either.
I'm quite sure it's linux/driver related but can't figure out what is the issue.

I found that when it occurs, wireshark gets some duplicate ping packets retransmission and ACK than usual. (don't know if related)

I have no idea what to do more about this.

Thanks for your help !

gedgon

Member

From: Poland

Registered: 2011-01-27

Posts: 95

Re: Strange wifi lag peaks with TP-WN722N and ath9k_htc

https://bbs.archlinux.org/viewtopic.php … 6#p1600346