U-Boot atheros PHY support and cubox ethernet

[Vladimir Oltean]

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;
 }

The next thing to check is to print the value of phydev->interface there.
7 is PHY_INTERFACE_MODE_RGMII,
8 is PHY_INTERFACE_MODE_RGMII_ID,
9 is PHY_INTERFACE_MODE_RGMII_RXID,
10 is PHY_INTERFACE_MODE_RGMII_TXID,

You want it to be 8.

Thanks,
-Vladimir