How to debug Ethernet connectivity

[Sascha Hauer]

Hi Atilla,

On Fri, Dec 06, 2013 at 11:21:25AM +0100, Atilla Filiz wrote:
> Hello
> 
> I have been tasked to debug a port of Barebox to our custom board. It
> has one Ethernet interface. All network related(dhcp, ping ...) tasks
> fail with "Network is down" error, although the link lights on my
> switch are on. So I did this on 2013.06:
> 
> --- barebox-2013.06.0.orig/net/
> eth.c    2013-06-02 12:24:06.000000000 +0200
> +++ barebox-2013.06.0/net/eth.c    2013-12-03 16:52:40.428089000 +0100
> @@ -142,12 +142,16 @@
> 
>      if (force || is_timeout(last_link_check, 5 * SECOND) ||
>              !eth_current->phydev->link) {
>          ret = phy_update_status(eth_current->phydev);
>          if (ret)
>              return ret;
>          last_link_check = get_time_ns();
>      }
> 
> +    return 0;
>      return eth_current->phydev->link ? 0 : -ENETDOWN;
>  }
> 
> This bypasses link detection and assumes the link is always up. This
> way, I got dhcp, ping and tftp working.
> 
> How can I debug this further to hunt down the Ethernet problem?
> Something seems wrong with my PHY settings. This is an iMX27 based
> board. Which files/functions/structures do I need to check?

Most likely the phy_addr field in fec_platform_data is wrong.

It could also be that the pinmux for the MDIO lines to the phy
is misconfigured.

Sascha

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