On Wed, Jun 17, 2020 at 12:55:18PM +0200, Russell King - ARM Linux admin wrote:
> The individual RGMII delay modes are more about what the PHY itself is
> asked to do with respect to inserting delays, so I don't think your
> patch makes sense.
This seems to be the same aspect that Vladimir Oltean remarked. I agree
that the relevant hunk should be dropped.
> > --- a/drivers/net/ethernet/cadence/macb_main.c
> > +++ b/drivers/net/ethernet/cadence/macb_main.c
> > @@ -514,7 +514,7 @@ static void macb_validate(struct phylink_config *config,
> > state->interface != PHY_INTERFACE_MODE_RMII &&
> > state->interface != PHY_INTERFACE_MODE_GMII &&
> > state->interface != PHY_INTERFACE_MODE_SGMII &&
> > - !phy_interface_mode_is_rgmii(state->interface)) {
> > + state->interface != PHY_INTERFACE_MODE_RGMII_ID) {
>
> Here you reject everything except PHY_INTERFACE_MODE_RGMII_ID.
>
> > bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
> > return;
> > }
> > @@ -694,6 +694,13 @@ static int macb_phylink_connect(struct macb *bp)
> > struct phy_device *phydev;
> > int ret;
> >
> > + if (of_phy_is_fixed_link(dn) &&
> > + phy_interface_mode_is_rgmii(bp->phy_interface) &&
> > + bp->phy_interface != PHY_INTERFACE_MODE_RGMII) {
>
> but here you reject everything except PHY_INTERFACE_MODE_RGMII. These
> can't both be right. If you start with PHY_INTERFACE_MODE_RGMII, and
> have a fixed link, you'll have PHY_INTERFACE_MODE_RGMII passed into
> the validate function, which will then fail.
For a fixed-link, the validation function is never called. Therefore, it
cannot reject PHY_INTERFACE_MODE_RGMII. It works in practice.
However, the consensus is to not reject that mode in the validation
function.
Helmut
