Re: [PATCH net-next v2] net: axienet: Properly handle PCS/PMA PHY for 1000BaseX mode

[Russell King - ARM Linux admin <linux@armlinux.org.uk>]

On Mon, Oct 26, 2020 at 06:57:00PM +0000, Radhey Shyam Pandey wrote:
> > +	switch (state->interface) {
> > +	case PHY_INTERFACE_MODE_NA:
> > +	case PHY_INTERFACE_MODE_1000BASEX:
> > +	case PHY_INTERFACE_MODE_SGMII:
> > +	case PHY_INTERFACE_MODE_GMII:
> > +	case PHY_INTERFACE_MODE_RGMII:
> > +	case PHY_INTERFACE_MODE_RGMII_ID:
> > +	case PHY_INTERFACE_MODE_RGMII_RXID:
> > +	case PHY_INTERFACE_MODE_RGMII_TXID:
> > +		phylink_set(mask, 1000baseX_Full);
> > +		phylink_set(mask, 1000baseT_Full);
> > +		if (state->interface == PHY_INTERFACE_MODE_1000BASEX)
> > +			break;
> 
> 100BaseT and 10BaseT can be set in PHY_INTERFACE_MODE_MII if we 
> allow fallthrough here.

The above is actually correct (at the moment) since we don't yet support
rate adapting 1G PHYs.

> > +	if (lp->phy_mode == PHY_INTERFACE_MODE_SGMII ||
> > +	    lp->phy_mode == PHY_INTERFACE_MODE_1000BASEX) {
> > +		if (!lp->phy_node) {
> > +			dev_err(&pdev->dev, "phy-handle required for
> > 1000BaseX/SGMII\n");
> > +			ret = -EINVAL;
> > +			goto free_netdev;
> > +		}
> > +		lp->pcs_phy = of_mdio_find_device(lp->phy_node);
> > +		if (!lp->pcs_phy) {
> > +			ret = -EPROBE_DEFER;
> 
> Are we assuming the error is always EPROBE_DEFER?

of_mdio_find_device() returning NULL when the argument is non-NULL
just means it wasn't found - which isn't an "error".

-- 
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