LS1046a - downgrade the speed of SGMII.9 or SGMII.10 to 1Gbps SGMII in Linux

[masonyen]

Is it possible to set SerDes1 RCW 2223, then down grade the speed of SGMII.9 or SGMII.10 to 1Gbps SGMII in Linux for LS1046A custom board?

SerDes1 2223 2.5G SGMII.9 2.5G SGMII.10 2.5G SGMII.5 SGMII.6

[yipingwang]

In Linux, you could run the following command to down grade the speed of SGMII.9 or SGMII.10 to 1Gbps.

$ ethtool -s fm1-mac9 speed 1000 duplex full autoneg off

[masonyen]

Hi Yiping,

The command you provided doesn't work. Does this command only work with Phy not Phy-less? The fm1-mac9 of our LS1046A custom board is phyless, we use a 1G SFP transceiver instead(ABCU-5740ARZ). I tried to trace the linux code.  The genphy_read_status routine sets fm1-mac9 speed to 10Mbps. It seems incorrect.

ethtool -s fm1-mac9 speed 1000 duplex full autoneg off

Cheers,

Mason

[yipingwang]

Hello Mason,

Please define fixed-link device node as the following in the dts file.

ethernet@f0000 { /* 10GEC1 */

        fixed-link = <0 1 1000 0 0>;
        phy-connection-type = "sgmii";
};

Old, deprecated 'fixed-link' binding:

* A 'fixed-link' property in the Ethernet MAC node, with 5 cells, of the
form <a b c d e> with the following accepted values:
- a: emulated PHY ID, choose any but but unique to the all specified
fixed-links, from 0 to 31
- b: duplex configuration: 0 for half duplex, 1 for full duplex
- c: link speed in Mbits/sec, accepted values are: 10, 100 and 1000
- d: pause configuration: 0 for no pause, 1 for pause
- e: asymmetric pause configuration: 0 for no asymmetric pause, 1 for
asymmetric pause

Thanks,

Yiping

[masonyen]

Hi Yiping,

For fm1-mac9, it is already a fixed-link. Please see below. Any other solution?

    ethernet@f0000 {
        fixed-link = <2 1 1000 0 0>;
        phy-connection-type = "sgmii-2500";        
    };

I also tried below fixed-link define for fm1-mac9. Still not working.

    ethernet@f0000 {
        fixed-link = <2 1 1000 0 0>;
        phy-connection-type = "sgmii";        
    };

[yipingwang]

Hello Mason,

You could use SRDS_PRTCL_S1 RCW[128-143]=0x2333. This will provide:

Lane A = 2.5G SGMII.9, PLL2

Lane B = SGMII.10, PLL1

Lane C = SGMII.5, PLL1

Lane D = SGMII.6, PLL1

Thanks,

Yiping