igb driver for I210 increments the carrier_transitions count by 2

[sb37]

PROBLEM: When the eth0 interface is brought down and up quickly, carrier_transitions count sometimes increments by 2

DESCRIPTION:
This issue has been observed on multiple different systems that use I210 device and IGB driver. It has been observed under both Debian Ver 12 and Ubuntu ver 22.04. The following cli were used to reproduce the issue:

$ sudo ifconfig eth0 down; sudo ifconfig eth0 up

The device name eth0 is different for different systems so appropriate device name was used as necessary.

After running the cli, the carrier_transition count was checked using the counter in /sys/devices - one example is:

$ cat /sys/devices/pci0000:00/0000:00:1c.6/0000:04:00.0/net/eno3/carrier_down_count

While the issue does not happen every time, it can be easily seen if a script runs the cli and checks the counter soon after. The counters are checked after one second delay and the next CLI is called after 5-10sec delay.

When the netlink messages are monitored using a user level program, the following is observed

Normally:
DOWN NOT-RUNNING
UP NOT-RUNNING
UP RUNNING

In Error case:
DOWN NOT-RUNNING
UP RUNNING
UP NOT-RUNNING
UP RUNNING

[Poojitha]

Hi sb37,

Thank you for reaching out to the Intel support. We acknowledge receipt of your concern and want to assure you that assisting you is our top priority. To effectively troubleshoot the issue you're facing, we require some additional information from your end.

Could you kindly provide the following details?

1)Kindly share the complete product details.

2)Could you please share the system information?

Your prompt response with this information will greatly assist us in diagnosing and resolving the issue as quickly as possible.

We look forward to hearing from you soon.

Best regards,

Poojitha N

Intel Customer Support Technician

[Poojitha]

Hi sb37,

Greetings for the day!

We are following up to check if you were able to find the information we requested. Kindly confirm at your earliest convenience, so that we can continue assisting you in resolving this matter.

 We appreciate your understanding!

 Regards,

 Poojitha

 Intel Customer Support Technician

[Simon-Intel]

Hi sb37,

Thank you for contacting Intel.

This is the second follow-up regarding the reported issue. We're eager to ensure a swift resolution and would appreciate any updates or additional information you can provide.

Please feel free to respond to this message at your earliest convenience.

Best regards,

Simon

Intel Customer Support Technician