topic About Ethernet TX ring dump in i.MX Processors

About Ethernet TX ring dump

taihei_ishido — Fri, 05 Jun 2020 04:30:39 GMT

When data communication via Ethernet, data communication was disconnected.

In this case, we saw following message log using iMX6soloX.

ーーーーーーーーーーーーーーーー

fec 2188000.ethernet eth0: TX ring dump
Nr SC addr len SKB
0 0x1c00 0x00000000 1460 (null)
0x1400 0x00000000 54 (null)
0x1c00 0x00000000 1460 (null)
0x1400 0x00000000 54 (null)

ーーーーーーーーーーーーーーーー

How can I resolve this problem?

My setting is the following.

- I used iPerf3

PC(iperf3 client) --- iMX6sx device -- PC(iperf3 server)

- iMX6sx device uses 1000BASE LAN. LAN is connected to PCs.

- iperf3 command is the following.

Client : iperf3 -t 86400 -c 192.168.2.100 -b 250M --logfile xxxxx

Server: iperf3 -s --logfile yyyyyy

[Note]

- I already refer community https://community.nxp.com/thread/432988 .

This patch is already included.

Thanks,

Re: About Ethernet TX ring dump

Yuri — Wed, 10 Jun 2020 04:53:09 GMT

Hello,

I found the following recommendation, which can help:
In fec.h, you can find TX_RING_SIZE line, like below; and you can increase it.

#define TX_RING_SIZE 512 ( or 1024 etc)

Regards,

Yuri.

Re: About Ethernet TX ring dump

taihei_ishido — Wed, 10 Jun 2020 06:00:39 GMT

Hi Yuri-san,

Thank you for your comment.

I modified TX_RING_SIZE to 1024.
However, I saw this issue again.

Are there other ways to improve?　

Thanks,

Taihei.

Re: About Ethernet TX ring dump

Yuri — Thu, 11 Jun 2020 05:33:11 GMT

Hello,

perhaps it makes sense to try iperf2 instead of iperf3, as mentioned in the following

Community thread.

IMX6D Poor Ethernet Performance (UDP)

Regards,

Yuri.

Re: About Ethernet TX ring dump

taihei_ishido — Fri, 12 Jun 2020 07:26:37 GMT

Hi Yuri,

Thank you for your comment.

I used iperf2. As a result, I saw Tx ring dump. However, iperf2 TCP communication did not disconnect.

iperf	result	Note
iperf3	Tx ring dump occurred	TCP data communication was disconnected
iperf2	Tx ring dump occurred	TCP data communication was not disconnected

I have a question from the results above.

If Ether Tx ring dump occurred, is it possible to data communication continually on same session?

Regarding the community thread (IMX6D Poor Ethernet Performance (UDP)) and Tx ring dump issues above, are the iperf3 issue related?

Why does Ether Tx ring dump happen?

Thanks,

Taihei

Re: About Ethernet TX ring dump

Yuri — Tue, 16 Jun 2020 11:14:24 GMT

Hello,

Although the ENET restriction of i.MX6Q is not mentioned for i.MX 6SX, nevertheless,

I think, general system performance issue can take place here. Is it possible to decrease
Ethernet load in Your tests?

Regards,

Yuri.

Re: About Ethernet TX ring dump

taihei_ishido — Wed, 17 Jun 2020 13:16:34 GMT

Hi,

Thank you for your comment.

> I think, general system performance issue can take place here.

Does high-speed Ether communication cause "Tx ring dump" due to general system performance?

Also, is there a limit to the communication speed of Ether?

I don't have the results of tests that have reduced the load on Ethernet.

If I have it, I'll share to you.

Thanks,

Taihei

Re: About Ethernet TX ring dump

Yuri — Thu, 18 Jun 2020 08:58:58 GMT

Hello,

i.MX6SX single Ethernet 1G connection should work, but I am not sure
regarding dual ENET, using just for Ethernet applications, such Ethernet switch.

Regards,

Yuri.