Ethernet LEDs won't turn off when i unplug the Ethernet cable

Technical Support
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1

Hello,
I’m working on a custom board equipped with a Colibri iMX6 module and the LAN9500A USB to Ethernet controller without EEPROM for the network interface. Operating system is Linux (Yocto). The LAN9500A is connected to a RJ45 jack with integrated Magnetics and LEDs.

I can see the LAN9500A is detected and correct driver is loaded…, Everything works fine when a cable is plugged…

The only problem is that when I unplug the Ethernet cable from the RJ45 socket, Linux does not detect it, and the status LEDs stay ON or may be blinking… However, if I again plug the network cable, link goes down then up again and it works okay…

Does anyone have any ideas?

2

Hi

The PHY should be able to do the link detection and the driving autonomous without the help of the driver on the module.

So at first you should check the reference schematics of Microchip against your design. Maybe the Microchip’s Layout Guidelines for the LAN95xx family might give some indication what goes wrong.

Can you provide the full output of dmesg, maybe the driver outputs some debug information.

Max