U-Boot atheros PHY support and cubox ethernet

[Vladimir Oltean]

On Wed, 17 Jun 2020 at 00:35, Tom Rini <trini at konsulko.com> wrote:
>
> On Tue, Jun 16, 2020 at 11:37:17PM +0300, Vladimir Oltean wrote:
> > On Tue, 16 Jun 2020 at 23:31, Tom Rini <trini at konsulko.com> wrote:
> > >
> > > On Tue, Jun 16, 2020 at 11:21:08PM +0300, Vladimir Oltean wrote:
> > > > On Tue, 16 Jun 2020 at 23:10, Tom Rini <trini at konsulko.com> wrote:
> > > > >
> > > > > On Tue, Jun 16, 2020 at 10:58:26PM +0300, Vladimir Oltean wrote:
> > > > > > Hi Tom,
> > > > > >
> > > > > > On Tue, 16 Jun 2020 at 22:55, Tom Rini <trini at konsulko.com> wrote:
> > > > > > >
> > > > > > > Hey all,
> > > > > > >
> > > > > > > In commit 4346df3392c0 ("phy: atheros: Make RGMII Tx delays actually
> > > > > > > configurable for AR8035") we brought in changes to get in to line with
> > > > > > > upstream linux kernel support for this PHY and in turn deal with more
> > > > > > > "driver was wrong, DT was wrong too" changes.  Now the problem I have is
> > > > > > > that ethernet on my Hummingboard doesn't work AND as far as I can tell,
> > > > > > > the DTB is correct and saying phy-mode = "rgmii-id" now not "rgmii".  It
> > > > > > > also looks to match what's in v5.7 for the kernel.  What do I need to do
> > > > > > > here next?  Thanks!
> > > > > > >
> > > > > > > --
> > > > > > > Tom
> > > > > >
> > > > > > Reverting 4346df3392c0 makes your interface work?
> > > > >
> > > > > Yup.
> > > > >
> > > > > > What is the DTS path that your hummingboard uses?
> > > > >
> > > > > Good question.  Per board/solidrun/mx6cuboxi/mx6cuboxi.c:
> > > > > /*
> > > > >  * This is not a perfect match. Avoid dependency on the DM GPIO driver
> > > > >  * needed
> > > > >  * for accurate board detection. Hummingboard2 DT is good enough for
> > > > >  * U-Boot on
> > > > >  * all Hummingboard/Cubox-i platforms.
> > > > >  */
> > > > > so arch/arm/dts/imx6dl-hummingboard2-emmc-som-v15.dts is the base.  But
> > > > > the board really is the original hummingboard platform.  Thanks!
> > > > >
> > > > > --
> > > > > Tom
> > > >
> > > > Does it work if you say PHY_INTERFACE_MODE_RGMII_ID here?
> > > > https://gitlab.denx.de/u-boot/u-boot/-/blob/master/drivers/net/fec_mxc.c#L1232
> > >
> > > No change.  And to be clear, I bisect'd the issue down and at that
> > > commit, reverting it fixes ethernet.  It doesn't revert cleanly (nor
> > > obviously to me) on master.
> > >
> > > --
> > > Tom
> >
> > On master, the revert would look like this:
> >
> > diff --git a/drivers/net/phy/atheros.c b/drivers/net/phy/atheros.c
> > index 13f7275d1706..5ba639e8119f 100644
> > --- a/drivers/net/phy/atheros.c
> > +++ b/drivers/net/phy/atheros.c
> > @@ -124,6 +124,7 @@ static int ar8021_config(struct phy_device *phydev)
> >
> >  static int ar803x_delay_config(struct phy_device *phydev)
> >  {
> > +       int regval;
> >         int ret;
> >
> >         if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
> > @@ -138,6 +139,10 @@ static int ar803x_delay_config(struct phy_device *phydev)
> >         else
> >                 ret = ar803x_enable_rx_delay(phydev, false);
> >
> > +       phy_write(phydev, MDIO_DEVAD_NONE, 0x1d, 0x05);
> > +       regval = phy_read(phydev, MDIO_DEVAD_NONE, 0x1e);
> > +       phy_write(phydev, MDIO_DEVAD_NONE, 0x1e, (regval|0x0100));
> > +
> >         return ret;
> >  }
>
> This alone is not enough.
>

So if this is not enough, then I'd go back to bisecting. I'd rebase
right after 8737c65fe4e3 ("phy: atheros: consolidate
{ar8031|ar8035}_config()"), create a new patch on
board/solidrun/mx6cuboxi/mx6cuboxi.c which changes RGMII to RGMII_ID,
confirm it works (according to what you've said so far, it should),
then bless it as "git bisect good", and let the fun start :)