On Thu, Jun 26, 2025 at 03:10:50PM +0530, Siddharth Vadapalli wrote:
> On Tue, Jun 24, 2025 at 12:53:33PM +0200, Matthias Schiffer wrote:
>
> Hello Matthias,
>
> > All am65-cpsw controllers have a fixed TX delay, so the PHY interface
> > mode must be fixed up to account for this.
> >
> > Modes that claim to a delay on the PCB can't actually work. Warn people
> > to update their Device Trees if one of the unsupported modes is specified.
> >
> > Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> > Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
> > Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
> > ---
> > drivers/net/ethernet/ti/am65-cpsw-nuss.c | 27 ++++++++++++++++++++++--
> > 1 file changed, 25 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > index f20d1ff192efe..519757e618ad0 100644
> > --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > @@ -2602,6 +2602,7 @@ static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
> > return -ENOENT;
> >
> > for_each_child_of_node(node, port_np) {
> > + phy_interface_t phy_if;
> > struct am65_cpsw_port *port;
> > u32 port_id;
> >
> > @@ -2667,14 +2668,36 @@ static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
> >
> > /* get phy/link info */
> > port->slave.port_np = of_node_get(port_np);
> > - ret = of_get_phy_mode(port_np, &port->slave.phy_if);
> > + ret = of_get_phy_mode(port_np, &phy_if);
> > if (ret) {
> > dev_err(dev, "%pOF read phy-mode err %d\n",
> > port_np, ret);
> > goto of_node_put;
> > }
> >
> > - ret = phy_set_mode_ext(port->slave.ifphy, PHY_MODE_ETHERNET, port->slave.phy_if);
> > + /* CPSW controllers supported by this driver have a fixed
> > + * internal TX delay in RGMII mode. Fix up PHY mode to account
> > + * for this and warn about Device Trees that claim to have a TX
> > + * delay on the PCB.
> > + */
> > + switch (phy_if) {
> > + case PHY_INTERFACE_MODE_RGMII_ID:
> > + phy_if = PHY_INTERFACE_MODE_RGMII_RXID;
> > + break;
> > + case PHY_INTERFACE_MODE_RGMII_TXID:
> > + phy_if = PHY_INTERFACE_MODE_RGMII;
> > + break;
> > + case PHY_INTERFACE_MODE_RGMII:
> > + case PHY_INTERFACE_MODE_RGMII_RXID:
> > + dev_warn(dev,
> > + "RGMII mode without internal TX delay unsupported; please fix your Device Tree\n");
>
> Existing users designed boards and enabled Ethernet functionality using
> "rgmii-rxid" in the device-tree and implementing the PCB traces in a
> way that they interpret "rgmii-rxid". So their (mis)interpretation of
> it is being challenged by the series. While it is true that we are updating
> the bindings and driver to move towards the correct definition, I believe that
> the above message would cause confusion. Would it be alright to update it to
> something similar to:
>
> "Interpretation of RGMII delays has been corrected; no functional impact; please fix your Device Tree"
It is dev_warn() not dev_err(), so it should be read as a warning. And
the device will continue to probe and work. So I think the message is
O.K. What we don't want is DT developers thinking they can just ignore
it. So i would keep it reasonably strongly worded.
Andrew
