On Tue, May 15, 2018 at 10:18:56AM +0200, Marco Felsch wrote:
> From: Markus Niebel <Markus.Niebel@xxxxxx>
>
> The micrel KSZ9031 phy has a optional clock pin (CLK125_NDO) which can be
> used as reference clock for the MAC unit. The clock signal must meet the
> RGMII requirements to ensure the correct data transmission between the
> MAC and the PHY. The KSZ9031 phy does not fulfill the duty cycle
> requirement if the phy is configured as slave. For a complete
> describtion look at the errata sheets: DS80000691D or DS80000692D.
>
> The errata sheet recommends to force the phy into master mode whenever
> there is a 1000Base-T link-up as work around. Only set the
> "micrel,force-master" property if you use the phy reference clock provided
> by CLK125_NDO pin as MAC reference clock in your application.
>
> Attenation, this workaround is only usable if the link partner can
> be configured to slave mode for 1000Base-T.
Thanks for adding all the documentation.
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew
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