This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DP83848J: DP83848J

Part Number: DP83848J

 

Hello,

Our customer who used DP83848J and met a question, after DP83848J  power up, the LED of LED_LINk is light , should it be light after the insertion the Ethernet cable? Below is the configuration of dts with Kenel. Could you please help to analysis? 

&gmac_clkin {
clock-frequency = <50000000>;
};

&gmac {
//pmu_regulator = "act_ldo5";
//pmu_enable_level = <1>; //1->HIGH, 0->LOW
//power-gpio = <&gpio0 GPIO_A6 GPIO_ACTIVE_HIGH>;
reset-gpio = <&gpio2 GPIO_D0 GPIO_ACTIVE_HIGH>;
/* phyirq-gpio = <&gpio0 GPIO_D1 GPIO_ACTIVE_LOW>; */
phy-mode = "rmii";
clock_in_out = "output";
tx_delay = <0x30>;
rx_delay = <0x10>;
};

Best regards

Kailyn

 

  • Hello

    rk3128_box:/ # echo 0x19 > /sys/devices/2008c000.eth/stmmac-0:01/phy_reg

    rk3128_box:/ # cat /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue

    phy reg 0x19 = 0x8001

    rk3128_box:/ #

    rk3128_box:/ #

    1 > /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue <

    rk3128_box:/ #

    rk3128_box:/ #

    rk3128_box:/ #

    rk3128_box:/ # cat /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue

    phy reg 0x19 = 0xffff

    execute command as below:

    echo 0x19 > /sys/devices/2008c000.eth/stmmac-0:01/phy_reg

    cat /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue

    phy reg 0x19 = 0x8001

    echo 0x8011 > /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue

    cat /sys/devices/2008c000.eth/stmmac-0:01/phy_regValue

    phy reg 0x19 = 0xffff

    the phy reg  0x19 result is 0xffff。why?

    question)

    1:can't write data to reg 0x19,why?  DP83848J has write mode?

    thank you so much。

    top-tech  from Shenzhen

  • Hello,

    Can you check if extended register method is used to access register 0x19? Reading 0x19 will tell us how the LED is configured. Can you also check how LED is connecting in schematics? Depending on what strap mode is used, it should be connected as per 'Figure 6-1. AN Strapping and LED Loading Example' in the datasheet.

    -Regards
    Aniruddha
  • Can you check if extended register method is used to access register 0x19?
    I don't konw how to check it,if you have any suggest tell me please

    my company hardware engineer will check schematic
  • our hardware engineer can't find any problem in schematic
  • 1: modify my code as below。

    --- a/kernel/drivers/net/phy/mdio_bus.c
    +++ b/kernel/drivers/net/phy/mdio_bus.c
    @@ -289,6 +289,11 @@ int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)

    BUG_ON(in_interrupt());

    + //if(regnum==0x19 || regnum==0x18){
    + printk("********** %s val=0x%x",__func__, val);
    + dump_stack();
    + //}
    +

    2: kernel/drivers/net/ethernet/rockchip/gmac/stmmac_main.c

    @@ -3409,6 +3410,10 @@ static int __init stmmac_init(void)
    {
    int ret;

    + pr_info("********** __file__ = %s __func__ = %s \n",__FILE__,__func__);

    3: bootup device ,before print function stmmac_init(),the LED_link is light。but can't find any message about “mdiobus_write”
  • Hi,

    Have you tried writing to other registers? Can you successfully change other registers?

    -Regards

    Aniruddha