AMCC 440EP phy detection

[Grant Likely]

On Tue, Apr 7, 2009 at 9:32 AM, Eddie Dawydiuk <eddie at embeddedarm.com> wrote:
> Hello,
>
> I'm working on a board based on the Yosemite AMCC 440EP eval board. I'm
> having some difficulty getting both network interfaces working. The first
> problem I found is the ibm_newemac driver was detecting the two phys at
> address 0 and 1 where we have them wired for addresses 1 and 3. As a result
> I hardcoded the phy-address in the dts file. I then found I was able to
> receive and send data on eth1(phy-address 3) without incident. Although I
> found eth0 can receive data but I see no packets being transmitted(using a
> packet sniffer) and I see no indication from a software standpoint of any
> transmit failures. We are using Micrel KSZ8041FTL phys(RMII mode) where the
> Yosemite board used Micrel KS8721BL phys.  I've reviewed the schematic and
> it appears both phys are connected identically and I've seen this same
> failure on multiple boards. I thought the fact that the driver detected a
> phy at address 0 might be a clue, but I can't make much of the clue. So I
> thought I'd post this info in the hopes someone else might have run into a
> similar problem or have a suggestion.

Phy address 0 is the broadcast address.  All phys will usually respond
to address 0 accesses.  Off the top of my head, It sounds like one PHY
is responding to addresses 0 & 1, and the other phy isn't responding
at all.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.