[PATCH v2] net: phy: fix duplicate eth_phy binding

[Vinay Tilak, Pranav]

[AMD Official Use Only - AMD Internal Distribution Only]

Hi Marek,

> -----Original Message-----
> From: Marek Vasut <marek.vasut at mailbox.org>
> Sent: Wednesday, April 8, 2026 10:02 PM
> To: Vinay Tilak, Pranav <Pranav.VinayTilak at amd.com>; u-boot at lists.denx.de;
> Simek, Michal <michal.simek at amd.com>
> Cc: git (AMD-Xilinx) <git at amd.com>; Begari, Padmarao
> <Padmarao.Begari at amd.com>; Jerome Forissier
> <jerome.forissier at arm.com>; Tom Rini <trini at konsulko.com>; Peng Fan
> <peng.fan at nxp.com>; Lucien.Jheng <lucienzx159 at gmail.com>; Yao Zi
> <me at ziyao.cc>; SkyLake.Huang <skylake.huang at mediatek.com>; Siddharth
> Vadapalli <s-vadapalli at ti.com>; Marek Vasut
> <marek.vasut+renesas at mailbox.org>; Ramon Fried <rfried.dev at gmail.com>
> Subject: Re: [PATCH v2] net: phy: fix duplicate eth_phy binding
>
> On 4/8/26 10:58 AM, Pranav Tilak wrote:
> > When both CONFIG_PHY_ETHERNET_ID and CONFIG_DM_ETH_PHY are
> enabled,
> > eth_phy_binds_nodes() called from eth_post_bind() already binds the
> > ethernet PHY node to eth_phy_generic_drv. However,
> > phy_connect_phy_id() called via zynq_phy_init() -> phy_connect()
> > cannot attach to the already bound PHY device and creates a second
> > instance, resulting in duplicate entries in the dm tree:
> >
> > Fix this by guarding the phy_connect_phy_id() call in phy_connect()
> > with uclass_get_device_by_phandle() to skip re-binding if the PHY node
> > is already registered in UCLASS_ETH_PHY.
> >
> > Fixes: 68a4d1506109 ("net: phy: Bind ETH_PHY uclass driver to each new
> > PHY")
> > Signed-off-by: Pranav Tilak <pranav.vinaytilak at amd.com>
> > ---
> > Changes in v2:
> > - Move duplicate binding check to caller phy_connect()
> > - Update commit description
> >
> >   drivers/net/phy/phy.c | 9 +++++++--
> >   1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index
> > d7e0c4fe02d..cfca8328f1c 100644
> > --- a/drivers/net/phy/phy.c
> > +++ b/drivers/net/phy/phy.c
> > @@ -938,8 +938,13 @@ struct phy_device *phy_connect(struct mii_dev
> *bus, int addr,
> >   #endif
> >
> >   #ifdef CONFIG_PHY_ETHERNET_ID
> > -   if (!phydev)
> > -           phydev = phy_connect_phy_id(bus, dev, addr);
> > +   if (!phydev) {
> > +           struct udevice *phy_dev;
> > +
> > +           if (uclass_get_device_by_phandle(UCLASS_ETH_PHY, dev,
> > +                                            "phy-handle", &phy_dev))
> > +                   phydev = phy_connect_phy_id(bus, dev, addr);
> Shouldn't this binding check be closer to the beginning of phy_connect() ?
> Basically check whether the PHY driver is already bound at the beginning, and
> if so, you are done. I don't think that test is specific to
> CONFIG_PHY_ETHERNET_ID, is it ?

The check is placed inside phy_connect_phy_id() because that is the only code path that calls device_bind_driver_to_node() on the PHY node, which creates the duplicate. The other paths (phy_connect_fixed, NCSI, phy_connect_gmii2rgmii) do not bind the PHY node and are not affected.

Thanks & Regards,
Pranav Tilak