Unable to Enable Dual Ethernet Functionality on i.MX8QXP

[adnan_dst]

Hello,

I am working on an i.MX8QXP with a custom carrier board that includes two Ethernet interfaces (KSZ9031RNXVB-TRVAO).

When configuring a single Ethernet interface (ethphy0), the dmesg log shows the link is up at 10 Mbps half-duplex with flow control off, and the assigned IP is in the 169...* range. However, enabling autonegotiation allows eth0 to obtain an IP address and successfully handle tasks like pinging and file transfers.

The issue arises when enabling both Ethernet interfaces in the device tree. The logs indicate a failure to connect to the PHY for both eth0 and eth1. Additionally, the mdio info command in U-Boot reports: No MDIO bus found.

I have attached the relevant device tree files and schematics. Please advise on the steps required to get both Ethernet interfaces operational.

Thanks.

[adnan_dst]

We are using a single MDIO interface to connect two Ethernet PHYs. Is it acceptable to use a single MDIO interface in this setup, or are there any changes required to ensure proper functionality?

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

Could you share your <board>.c from u-boot?

Regards

[adnan_dst]

Hello,

Below is my board.c file from u-boot source.

Thanks!