Phy configuration with KNI interface

[Ghouse]

Hi All,

Iam using a NXP LS1046A based custom board,

I am connected the Fm1-mac5 interface to Marvell 88E1512 Phy which supports both optical and Electrical Ethernet interface,

Also at the Kernel level (when the OS boots up) iam able to use Electrical ethernet by default, however while changing to optical Interface iam changing the page to optical in 88E1512 (i used this link to configure Marvell phy https://community.nxp.com/t5/Other-NXP-Products/Read-Modify-Phy-registers-at-Linux-in-custom-board-b... ) and also fixing the interface to 1G with Autoneg Disabled using ethtool, and the optical interfcace is working fine in Kernel also.

Now, in my application iam using Fm1-mac5 for dpdk operation with KNI enabled for Fm1-mac5.

With KNI enabled, how can i access the Phy register (to read/modify) also how can i Disable Autoneg and Fix the speed to 1G ??

For disabling Autoneg i tried using ethtool, but iam not able to disable Autoneg using ethtool with KNI interface.

Please let me know what can be done to

1) read/modify phy registers for a KNI interface?

2) Disable Auto Neg and Fix the Speed to 1G of a KNI interface?

Please provide your help/support

Thank u

[Ghouse]

Hi All,

Please provide your support for the above topic.

Thank you

[yipingwang]

I am discussing this issue with NXP DPDK development team, please refer to my update later.

[Ghouse]

Hi @yipingwang ,

Any update on the issue mentioned above?

Please provide your help/support.

Thank you.

[yipingwang]

 KNI (https://doc.dpdk.org/guides-21.11/prog_guide/kernel_nic_interface.html)  is nothing but a pseudo soft network interface with kernel for exchanging DPDK traffic with kernel. It do not connect with the hardware based FMAN interface.

If you want to support both kernel traffic and DPDK traffic on the same physical ethernet interface – you can better use the VSP (Packet Split) mode.

https://github.com/NXP/dpdk/blob/22.11-qoriq/nxp/README_dpaa1_shared_mac

https://github.com/NXP/dpdk/blob/22.11-qoriq/nxp/README_pkt_split_app_demo  (without FMAN microcode)

[Ghouse]

Hi @yipingwang ,

Thank u very much for the reply.

Please note that in our application, all the traffic is handled by DPDK, only some management traffic that should be exchanged among the devices is only exchanged using the KNI interface using Socket based application code.

Our application is almost completed and migrating now to VSP will be difficult.

So, kindly let me know if in KNI is there a provision to

1) use Ethtool to disable Auto Neg and set speed to 1G

2) modify phy registers accessed by the KNI

Thank u.

[yipingwang]

That is what NXP share MAC does to direct management traffic to kernel directly, customer doesn't need modify any socket-based application upon VSP/shareMAC.

KNI interface has nothing to do with HW DPAA ports, dpdk DPAA ports are supposed to support phy change directly.

[yipingwang]

Please refer to the following update from the DPDK development team.

KNI is not the proper place to do the physical port control. It is just a pseudo/logical/soft interface. They can very well use the Tun/Tap interface as well for management traffic.

However, if they want to control the physical link properties, they can try doing from the DPDK based DPAA driver directly.

W.r.t. link control:  They can either change the DTS file to set the property as fix link  or use the following API to set the link speed as 1G in application

dpaa_update_link_speed

[Ghouse]

Hi @yipingwang ,

thank u for the reply,

Your Comment : if they want to control the physical link properties, they can try doing from the DPDK based DPAA driver directly.

Can u explain how this can be done.

Your Comment :W.r.t. link control: They can either change the DTS file to set the property as fix link or use the following API to set the link speed as 1G in application. dpaa_update_link_speed

Plz can u explain in detail, how this can be done (preferably with some example).

Thank u very much.

[yipingwang]

Please refer to the following in fsl-ls1046a-rdb.dts.

ethernet@f2000 { /* 10GEC2 */

                fixed-link = <0 1 1000 0 0>;

                phy-connection-type = "xgmii";

        };

Please refer to Documentation/devicetree/bindings/net/ethernet-controller.yaml

[yipingwang]

From "dpdk/kernel/linux/kni/kni_net.c", I do not see ethtool support in kni driver to access PHY registers.
There is an 'ethtool" example in DPDK package, you can check it if it helps.
And for Linux PHY driver of DPDP Port, phy device is registered in "drivers/staging/fsl_qbman/fsl_usdpaa.c",