Subject: Re: Ethernet issue on imx6

From: Stephen Hemminger <[email-masked]>
Date: Thu, 12 Oct 2023 15:58:57 -0700

On Thu, 12 Oct 2023 22:46:09 +0200
Andrew Lunn <[email-masked]> wrote:

> > //192.168.1.1 is my host, so the below lines are from the board:
> > # iperf3 -c 192.168.1.1 -u -b100M
> > [  5]   0.00-10.05  sec   113 MBytes  94.6 Mbits/sec  0.044 ms  467/82603 (0.57%)  receiver
> > # iperf3 -c 192.168.1.1 -u -b90M
> > [  5]   0.00-10.04  sec  90.5 MBytes  75.6 Mbits/sec  0.146 ms  12163/77688 (16%)  receiver
> > # iperf3 -c 192.168.1.1 -u -b80M
> > [  5]   0.00-10.05  sec  66.4 MBytes  55.5 Mbits/sec  0.162 ms  20937/69055 (30%)  receiver  
> 
> Have you tried playing with ‐‐pacing‐timer ?
> 
> Maybe iperf is producing a big bursts of packets and then silence for
> a while. The burst is overflowing a buffer somewhere? Smooth the flow
> and it might work better?
> 
>   Andrew
> 

Please post the basic system info.
Like kernel dmesg log.
All network statistics including ethtool.
Any special qdisc or firewall configuration.

Likely a hardware or driver bug that is doing something wrong
when a lot of packets are received.