Subject: Re: [2/3] via-rhine: de-isolate PHY

From: Manfred Spraul <[email-masked]>
Date: Sun, 08 Aug 2004 23:04:06 +0200

Roger Luethi wrote:

>  
>
>>I know that PHYs go into isolate mode if the startup id is wired to 0, 
>>    
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>Wouldn't that be s/go/can go/ ?
>
>  
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I don't have the MII standard, my knowledge is from the DP83840A specs:
The pin description contains a section about the phy ids:
During power up five pins are latched to determine the initial phy address.
Then the following sentence in bold: "An address selection of all zeros 
(00000) will result in a PHY isolation condition".

I've reread the DP specs and I now think that your current patch is 
sufficient:
The isolate state is independant from the phy address - a non-zero phy 
can be in isolate mode and the phy zero can be non-isolated. The phy id 
just sets the power-up value of the isolate bit: 0 means start isolated, 
non-zero means start non-isolated.

If this is really true then handling phy 0 is trivial:
First scan 1-31. If nothing found: try 0. If a phy is found: clear the 
isolate bit and then use phy 0.

--
    Manfred