Subject: Re: 405 MII-PHY communication problem (was: Re: PPC405gp enet Soft Reset)

From: "David Müller (ELSOFT AG)" <[email-masked]>
Date: Tue, 19 Feb 2002 13:05:44 +0100

Hi

The problem with the even-numbered PHY register addresses seems to be
caused by a too weak or totally missing pullup resistor on the MDIO line.

David Müller (ELSOFT AG) wrote:
>
> Hi
>
> andrew may wrote:
>
>> On Mon, Feb 11, 2002 at 12:55:05PM +0100, David Müller (ELSOFT AG) wrote:
>>
>>> Hi
>>>
>>> andrew may wrote:
>>>
>>>> Here is a log from ppcboot since it is easy to test this there
>>>> without doing
>>>> a kernel build. My phy is at address 0x1f.
>>>>
>>>> => mii read 0x1 2
>>>> 07FF
>>>> => mii read 0x1 3
>>>> read err 3
>>>> a2: read: EMAC_STACR=0xffffc023, i=2
>>>> Error reading from the PHY
>>>> 07FF
>>>>
>>>>
>>> I'm seeing this error too on our boards. But i'm not certain, if it's a
>>> problem of the MII controller in the 405 or a problem of the LXT971.
>>> What revision of the 405 do you have? What clock frequency your 405
>>> run at?
>>>

[old stuff deleted]

Dave

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