TDA4VM: Ethernet link up and down detection problem

Nikola Cetic

Part Number: TDA4VM

Tool/software:

Hi,

I am having issue with ethernet interface up and down for one interface which driver is running on R5F with freertos running on it. Linux doesn't update /sys/class/net/dl-eth0/ files according to wire plugged in or plugged out, it keeps previous states.

Here are outputs of /sys/class/net/dl-eth0/.

First image is after booting where UTP cable is not plugged in. Second is after plugging in, and third after plugging out cable from that interface. As you can see carrier always stays at 1, but in the other port which driver is fully implemented on Linux host side, carrier is set to 0 if cable is not plugged in else it is set to 1. Also operstate: is always set to unknown regardles of cable plugged in or not.

PROCESSOR-SDK-LINUX-J721E: 08.04.00.11 (02 Sep 2022)

PROCESSOR-SDK-RTOS-J721E: 08.06.00.21 according to pdk_jacinto_<version> folder name

over 2 years ago

0 Tanmay Patil over 2 years ago

TI__Mastermind 42980 points

Hi,

Can you please explain what tis the dl-eth0 interface here? Is it an virtual MAC interface created when ethfw is running on R5F?

Also, what is the link-type of dl-eth0 interface, is it a switch port or MAC-only port?

Regards,
Tanmay

0 Nikola Cetic over 2 years ago in reply to Tanmay Patil

Prodigy 20 points

Yes it is a virtual MAC interface created when ethfw is running on R5F.

But answer to second question I do not know how to determine. Can you tell me how to check it?

0 Tanmay Patil over 2 years ago in reply to Nikola Cetic

TI__Mastermind 42980 points

Hi,

Can you provide the boot log. I can check this on that.

Regards,
Tanmay

0 Nikola Cetic over 2 years ago in reply to Tanmay Patil

Prodigy 20 points

Hi,

Here is boot log extracted using journalctl -b

5074.boot.log

Regards,

Nikola

+1 Tanmay Patil over 2 years ago in reply to Nikola Cetic

TI__Mastermind 42980 points

Hi Nikola,

It's a switch port and hence it doesn't support knowing the carrier state for external link.

It doesn't make sense for a switch port's link status to be communicated. A switch port in the case of ethfw, is directly connected to the CPSW host port while the external switch ports are the CPSW external ports. The switch port can receive/send data from/to any of the external switch port. The external links will be independent of the state of the switch port.

Essentially, if drawn a parallel between a scenario with an external switch, your link to the switch is independent on the other links on the switch. You will not have access to the up and down state of the link from any other link. In out case, the A72's link to the switch is internal to SoC and hence is always up.

Regards,
Tanmay

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TDA4VM: Ethernet link up and down detection problem

PROCESSOR-SDK-LINUX-J721E: 08.04.00.11 (02 Sep 2022)

PROCESSOR-SDK-RTOS-J721E: 08.06.00.21 according to pdk_jacinto_<version> folder name