Re: [EXTERNAL] Re: [EXTERNAL] Re: [EXTERNAL] Re: [PATCH v4 2/2] net: ti: icssg-prueth: Add ICSSG ethernet driver

From: Andrew Lunn
Date: Thu Feb 09 2023 - 08:55:21 EST


> 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