Ethernet issue

  • Hello,

    we've encountered an issue with the ethernet connection on the PicoCore imx8mm over PoE. After a while (hours or even days) it

    seems to get in an undefined state, see below, and we loose the connection. Could this be some driver issue? How can

    we solve it? We are using Linux Kernel fsimx8mm 5.15.131-F+S and basically just the standard default F&S image for now. The issue gets

    fixed after restarting the device. Please find some logs below.


    First restart:


    Second restart:

    Code
    1. # /etc/init.d/S40network restart
    2. Stopping network: ifdown: interface eth0 not configured
    3. OK
    4. Starting network: RTNETLINK answers: File exists
    5. Qualcomm Atheros AR8035 30be0000.ethernet-1:04: phy_poll_reset failed: -110
    6. fec 30be0000.ethernet eth0: Unable to connect to phy
    7. RTNETLINK answers: No such device
    8. FAIL



    Best regards,

    BS

  • Hello,


    we were testing the last couple of days. The error happens with and without PoE on our baseboard. The eth0 link suddenly switches to down (fec 30be0000.ethernet eth0: Link is Down). We recognize this as soon as our external client application looses connection to the PicoCore part. A restart of the interface is not possible anymore due to error phy_poll_reset failed: -110, Unable to connect to phy, No such device.


    Do you have any ideas so far? We can arrange remote access for F&S, if this would be helpful.


    Best regards,

    BS

  • Hello,


    did you find a way to reproduce the issue faster? Maybe with high loads?


    We do not configure the HW-PHY-RESET pin in linux to keep the settings from U-Boot while booting.

    Could you try to reset the PHY "by hand" an see if it starts again in case of the error?


    Code
    1. ifconfig eth0 down
    2. gpioset gpiochip0 5=0
    3. sleep 0.1
    4. gpioset gpiochip0 5=1
    5. ifconfig eth0 up



    Your F&S Support Team

  • Hello,


    thanks for your comment.


    We have been testing different scenarios over multiple days, but we still cannot reproduce the issue any faster yet.

    I wanted to reset the PHY manually, but it seems that gpioset needs to be added to the Buildroot image manually, as it’s not included by default. Is this correct? Do I also need to change something in the default device tree?


    Best regards,

    BS