Hi Andrew and Ninad,

quoted

Thanks. What will be the "phy-mode" value after you make these changes?

Will it be "rgmii-id" for MAC1..4?

It should be.

Perhaps we will keep using "rgmii", still add RGMII delay configure on MAC side.
The reason is we cannot be sure all PHYs have support for phy-mode property.
We will refer to the other MACs and PHYs driver about phy-mode and 
rx/tx-internal-delay-ps properties how they implement.

Currently, we will plan to implement RGMII delay in ftgmac100 driver based on
ethernet-controller.yaml.

At same time, we will think how to configure these phy-mode "rgmii-rxid", "rgmii-txid" 
and "rgmii-id in MAC driver.

quoted

If that is the case then I can test it with current configuration
which may add extra delays in the RX from PHY side.

I would then expect traffic will not flow correctly, and your see CRC errors,
because of double delays. It is however a useful test, because if it does
somehow work, it probably means the PHY driver is also broken with its
handling of delays. I don't know what PHY driver you are using, but those in
mainline should be correct, it is something i try to review carefully.

We will submit a series patch of RGMII delay in ftgmac100 driver to mainline.

Thanks,
Jacky