Subject: Re: [Query]: DSA Understanding

From: Andrew Lunn <[email-masked]>
Date: Wed, 25 Jul 2018 18:19:23 +0200

On Wed, Jul 25, 2018 at 09:39:50AM +0100, Lad, Prabhakar wrote:
> Hi,
> 
> We are trying to integrate a MAC to an external switch as following:
> 
> +-------------------+            +------------------+
> |                    | RGMII   |                    |
> |                    +------------+  KSZ9897   +------ 1000baseT MDI ("LAN1")
> |                    | PORT 6 |  7-port         +------ 1000baseT MDI ("LAN2")
> |    AM572x    |              |  Ethernet     +------ 1000baseT MDI ("LAN3")
> |     CPSW     |MIImgmt |  switch        +------ 1000baseT MDI ("LAN4")
> |                    +-------------+                  +------
> 1000baseT MDI ("LAN5")
> |                    |    SPI    |                    |
> |                    |              |                   |
> |                    |              |                   +------
> 1000baseT MII ("LAN7")
> |                    |              |                   |
> +------------------+             +------------------+

Please use a fixed size font, otherwise this is unreadable.

> 
> I have done all the configuration required for the MAC controller and
> enabled the KSZ driver in the kernel, I can see the following:
> ~$ ip link show
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
> mode DEFAULT group default qlen 1000
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state
> DOWN mode DEFAULT group default qlen 1000

eth0 is you master device. NO-CARRIER is bad, since that means you
cannot send/receive from from the switch. Are you using a fixed phy on
the CPSW? What does your device tree look like?

    Andrew