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

Manfred Spraul
2004-08-08T21:01:37Z

Roger Luethi wrote:

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>>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