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DP83TG720S-Q1: Enable Master/Slave mode

Part Number: DP83TG720S-Q1

Hi, 

On board we have DP83TG720S-Q1 integrated, and we are using the dp83tg720.c file (from you website) as a driver for 1000Base-T1 interface. 

By default, 1000baset1 interface is in the SLAVE mode when I check it with ethtool and it is not possible to modify it with ethtool -s 1000baset1 master-slave forced-master. It remains the "slave" all the time. 

I tried manually to set register 0x834 with 0xc001 value and register 0x900 with 0x000 value but it didn't help. 

Does the original driver support master/slave modes? If not, do you have a patch? 

Did I miss something? 

BR,
Maksim. 

  • Hi Maksim,

    Please use the attached driver file and let me know if this solves your issue.

    dp83tg720.c

    Regards,
    Rahul

  • Hi, Rahul,

    Thank you for response.

    I tried that file as it is and I got this now:
    # ethtool -s 1000baset1 master-slave forced-master
    netlink error: master/slave configuration not supported by device (offset 40)
    netlink error: Operation not supported

    also, there is no master-slave in the:
    # ethtool 1000baset1
    Settings for 1000baset1:
    Supported ports: [ MII ]
    Supported link modes: 1000baseT/Full
    Supported pause frame use: No
    Supports auto-negotiation: No
    Supported FEC modes: Not reported
    Advertised link modes: Not reported
    Advertised pause frame use: No
    Advertised auto-negotiation: No
    Advertised FEC modes: Not reported
    Speed: 1000Mb/s
    Duplex: Full
    Auto-negotiation: off
    Port: Twisted Pair
    PHYAD: 8
    Transceiver: external
    MDI-X: Unknown
    Supports Wake-on: d
    Wake-on: d
    Link detected: yes

    BR,
    Maksim. 

  • Hi Maksim,

    Are any external hardware straps configured on your board configure for master/ slave ?

    By default, MDI Slave mode is configured because there is an internal pulldown resistor on LED_0 pin.

    Additionally, bit[14] in the PMA_CTRL2 egister controls the MDI Master and MDI Slave configuration. When this bit is set, MDI Master mode is enabled.

    Please try enabling this bit using register write and test it out. I do not think our driver will be enabling the master or slave using ethtool, but let me check it on my end as well.

    Thanks,
    Rahul