Re: [PATCH net-next v3] net: phy: micrel: add phy-mode support for the KSZ9031 PHY

[David Miller]

From: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Date: Wed, 22 Apr 2020 09:21:37 +0200

> Add support for following phy-modes: rgmii, rgmii-id, rgmii-txid, rgmii-rxid.
> 
> This PHY has an internal RX delay of 1.2ns and no delay for TX.
> 
> The pad skew registers allow to set the total TX delay to max 1.38ns and
> the total RX delay to max of 2.58ns (configurable 1.38ns + build in
> 1.2ns) and a minimal delay of 0ns.
> 
> According to the RGMII v1.3 specification the delay provided by PCB traces
> should be between 1.5ns and 2.0ns. The RGMII v2.0 allows to provide this
> delay by MAC or PHY. So, we configure this PHY to the best values we can
> get by this HW: TX delay to 1.38ns (max supported value) and RX delay to
> 1.80ns (best calculated delay)
> 
> The phy-modes can still be fine tuned/overwritten by *-skew-ps
> device tree properties described in:
> Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
> 
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>

Applied, thank you.