> >> I am currently upstreaming the "Nitrogen 8m Mini board" that seems to not
> >> use a
> >> "normal" mdio bus but a "bitbanged" one with the fsl fec driver.
> >
> > Any idea why?
> >
> > Anyway, you should not replicate code, don't copy bitbanging code into
> > the FEC. Just use the existing bit-banger MDIO bus master driver.
>
> Right there should be no need for you to modify the FEC driver at all,
> there is an existing generic bitbanged MDIO bus driver here:
Hi Florian
Speculation on my part, until i hear back on the Why? question, but
i'm guessing the board has a wrong pullup on the MDIO line. It takes
too long for the PHY/FEC to pull the line low at the default
2.5MHz. bit-banging is much slower, so it works.
If i'm right, there is a much simpler fix for this. Use the
clock-frequency property for the MDIO bus to slow the clock down.
Andrew
