> Sure, I'll do that. In the list of all phy modes described in [1], I can only > see phy-mode "rgmii-txid", for which we can return -EINVAL. Is there any other > phy-mode that requires enabling/disabling TX internal delays? Please let me > know if any other phy-mode also needs this. I will add check for that as well. There are 4 phy-modes for RGMII. rgmii, rgmii-id, rmgii-rxid, rgmii-txid. rgmii-id, rgmii-txid both require TX delays. If you do that in the MAC you then need to pass rgmii-rxid and rgmii to the PHY respectively. rmii and rgmii-rxid requires no TX delays, which your SoC cannot do, so you need to return -EINVAl, The interpretation of these properties is all really messy and historically not very uniformly done. Which is why i recommend the MAC does nothing, leaving it to the PHY. That generally works since the PHYs have a pretty uniform implementation. But in your case, you don't have that option. So i suggest you do what is described above. Andrew