Re: [PATCH net-next] net: stmmac: dwmac-qcom-ethqos: Add support for 2.5G SGMII

[Andrew Lunn]

> Qualcomm ethernet HW supports 2.5G speed in overclocked SGMII mode.
> we internally term it as OCSGMII.

So it still does SGMII inband signalling? Not 2500BaseX signalling? It
is not actually compatible with 2500BaseX?

> End goal of these patches is to enable SGMII with 2.5G speed support.
> The patch in these series enabled up SGMII with 2.5 for cases where we
> don't have external phy. ( mac-to-mac connectivity)

So the other end needs to be an over clocked SGMII MAC, not 2500BaseX?

> The new patch posted extends this for the case when the MAC has an
> external phy connected. ( hence we are advertising fr 2.5G speed by adding
> 2500BASEX as supported interface in phylink)

And i assume it does not actually work against a true 2500BaseX
device, because it is doing SGMII inband signalling?
 
Hence Russell frustration with the whole 2.5G mess....

      Andrew