On Wed, Jun 17, 2020 at 01:21:53PM +0200, Helmut Grohne wrote:
> 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.
Hmm, I'm not so sure, but then I don't know exactly what code you're
using. Looking at mainline, even for a fixed link, you call
phylink_create(). phylink_create() will spot the fixed link, and
parse the description, calling the validation function. If that
fails, it will generate a warning at that point:
"fixed link %s duplex %dMbps not recognised"
It doesn't cause an operational failure, but it means that you end up
with a zero supported mask, which is likely not expected.
This is not an expected situation, so I'll modify your claim to "it
works but issues a warning" which still means that it's not correct.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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