Hi Support Team,
We are testing apalis imx8qm on-board wifi module with latest ycoto linux reference multimedia image v5.1.0, there is some strange behavior on ping delay on imx8 receive way communication, please find details test process and log as below, kindly please check if there is any clue or solution on this?
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connect dual antenna to apalis imx8 on-board wifi module.
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set up wifi connection according to here.
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interface mlan0 is successfully connected to AP and assigned ip address.
root@apalis-imx8:~# ifconfig mlan0
mlan0 Link encap:Ethernet HWaddr C0:E4:34:2F:C4:A1
inet addr:10.20.1.134 Bcast:10.20.1.255 Mask:255.255.255.0
inet6 addr: fe80::c2e4:34ff:fe2f:c4a1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:251052 errors:0 dropped:103 overruns:0 frame:0
TX packets:119956 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:378139502 (360.6 MiB) TX bytes:11199741 (10.6 MiB) -
start ping to my PC which conected to same LAN network with apalis imx8 wifi connection, all work well, the ping latency is less than 10ms consistently.
root@apalis-imx8:~# ping 10.20.1.150
PING 10.20.1.150 (10.20.1.150): 56 data bytes
64 bytes from 10.20.1.150: seq=0 ttl=64 time=4.667 ms
64 bytes from 10.20.1.150: seq=1 ttl=64 time=4.309 ms
64 bytes from 10.20.1.150: seq=2 ttl=64 time=4.460 ms
64 bytes from 10.20.1.150: seq=3 ttl=64 time=4.298 ms
64 bytes from 10.20.1.150: seq=4 ttl=64 time=4.293 ms
64 bytes from 10.20.1.150: seq=5 ttl=64 time=4.516 ms
64 bytes from 10.20.1.150: seq=6 ttl=64 time=4.445 ms
64 bytes from 10.20.1.150: seq=7 ttl=64 time=4.422 ms
64 bytes from 10.20.1.150: seq=8 ttl=64 time=4.326 ms -
but when testing ping from my PC to apalis imx8, the ping latency becomes high and unstable with range from several tens ms to more than 1000ms.
simon@simon-Latitude-5300:~$ ping 10.20.1.134
PING 10.20.1.134 (10.20.1.134) 56(84) bytes of data.
64 bytes from 10.20.1.134: icmp_seq=1 ttl=64 time=104 ms
64 bytes from 10.20.1.134: icmp_seq=2 ttl=64 time=329 ms
64 bytes from 10.20.1.134: icmp_seq=3 ttl=64 time=556 ms
64 bytes from 10.20.1.134: icmp_seq=4 ttl=64 time=784 ms
64 bytes from 10.20.1.134: icmp_seq=5 ttl=64 time=1012 ms
64 bytes from 10.20.1.134: icmp_seq=6 ttl=64 time=3.39 ms
64 bytes from 10.20.1.134: icmp_seq=7 ttl=64 time=230 ms
64 bytes from 10.20.1.134: icmp_seq=8 ttl=64 time=460 ms
64 bytes from 10.20.1.134: icmp_seq=9 ttl=64 time=685 ms
64 bytes from 10.20.1.134: icmp_seq=10 ttl=64 time=914 ms -
strange thing is when testing the ping action with an iperf3 tcp bandwidth testing between my PC and apalis imx8 running simultaneously, the ping latency result become low and stable with several tens ms, the test process and comparison log is as below
./ first start iperf3 server on apalis imx8
root@apalis-imx8:~# iperf3 -s
./ then start ping from my pc to imx8simon@simon-Latitude-5300:~$ ping 10.20.1.134
./ then start iperf3 client testing on my pc$ iperf3 -c 10.20.1.134 -t 20
./ waiting for iperf3 testing done and stop ping command
whloe ping permance log is as below. BTW, has also tried setting imx8 cpu governor to performance mode to make all cpu cores work under max frequency, but the test result is same, no difference.