Re: PHY issue with SJA1105Q/DP84849I Design

From: Andrew Lunn
Date: Fri Dec 29 2023 - 16:44:10 EST


> > If you are truly using MII, then you should remove the RGMII delay
> > properties, and since you are using a 6.1 kernel - hence after kernel
> > commit 5d645df99ac6 ("net: dsa: sja1105: determine PHY/MAC role from PHY
> > interface type") - you should be using phy-mode = "rev-mii" to put this
> > port in MII PHY ("RevMII") mode - to interoperate with the FEC in MII
> > MAC mode.
>
> Okay, I will remove RGMII delay. is phy-mode = "rev-mii" applicable to
> all ports or only for fec port4?

phy-mode indicates what the PHY should be doing. In this case, the
switch is taking the place of the PHY and so the switch MAC needs to
be revMII so that it acts like a PHY. For the other ports of the
switch, you have a real PHY connected, so you want MII.

Andrew