Re: [PATCH net-next v2 3/4] dt-bindings: net: Add RGMII internal delay for DP83869

[Dan Murphy]

Andrew

On 5/20/20 10:36 AM, Andrew Lunn wrote:
> > > Hi Dan
> > >
> > > Having it required with PHY_INTERFACE_MODE_RGMII_ID or
> > > PHY_INTERFACE_MODE_RGMII_RXID is pretty unusual. Normally these
> > > properties are used to fine tune the delay, if the default of 2ns does
> > > not work.
> > Also if the MAC phy-mode is configured with RGMII-ID and no internal delay
> > values defined wouldn't that be counter intuitive?
> Most PHYs don't allow the delay to be fine tuned. You just pass for
> example PHY_INTERFACE_MODE_RGMII_ID to the PHY driver and it enables a
> 2ns delay. That is what people expect, and is documented.

> Being able to tune the delay is an optional extra, which some PHYs
> support, but that is always above and beyond
> PHY_INTERFACE_MODE_RGMII_ID.

I am interested in knowing where that is documented. I want to RTM I 
grepped for a few different words but came up empty

Since this is a tuneable phy we need to program the ID. 2ns is the 
default value

Maybe I can change it from Required to Configurable or Used.

Dan


>       Andrew