Re: [PATCH net-next RFC V1 5/5] net: mdio: Add a driver for InES time stamping IP core.

Richard Cochran
2018-03-21T21:57:32Z

On Wed, Mar 21, 2018 at 10:44:36PM +0100, Andrew Lunn wrote:
> O.K, so lets do the 20 questions approach.

:)

> As far as i can see, this is not an MDIO device. It is not connected
> to the MDIO bus, it has no MDIO registers, you don't even pass a valid
> MDIO address in device tree.

Right. There might very well be other products out there that *do*
use MDIO commands. I know that there are MII time stamping asics and
ip cores on the market, but I don't know all of their creative design
details.

> It it actually an MII bus snooper? Does it snoop, or is it actually in
> the MII bus, and can modify packets, i.e. insert time stamps as frames
> pass over the MII bus?

It acts like a "snooper" to provide out of band time stamps, but it
also can modify packets when for the one-step functionality.

> When the driver talks about having three ports, does that mean it can
> be on three different MII busses?

Yes.

HTH,
Richard