[PATCH v6] net: phy: fix duplicate eth_phy binding

[Pranav Tilak]

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 phy_connect() also binds the same PHY node, resulting in
duplicate entries in the DM tree.

Fix this by introducing phy_connect_dm_bound() which checks if the PHY
is already bound via uclass_find_device_by_phandle(). If so, it gets
the phy_device via phy_find_by_mask() since the udevice does not store
a phy_device pointer and the phy_device can only be obtained by
scanning the MDIO bus. The phydev->node is then set from the
already-bound DM device. This skips the generic binding methods
in phy_connect() when the PHY is already DM-bound.

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 v6:
- Introduce phy_connect_dm_bound() helper to handle already DM-bound PHY
- Extend commit message to explain why phy_find_by_mask() is needed

Changes in v5:
- Use int ret instead of bool phy_bound and goto out

Changes in v4:
- Removed IS_ENABLED(CONFIG_DM_ETH_PHY), use runtime check via
  uclass_find_device_by_phandle()
- Fix indentation of binding methods block
- Assign phydev->node from the bound DM device's ofnode

Changes in v3:
- Moved duplicate binding check to beginning of phy_connect()

Changes in v2:
- Move duplicate binding check to caller phy_connect()
- Update commit description

 drivers/net/phy/phy.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index d7e0c4fe02d..f2e9b2a9820 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -20,6 +20,7 @@
 #include <asm-generic/gpio.h>
 #include <dm/device_compat.h>
 #include <dm/of_extra.h>
+#include <dm/uclass-internal.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -921,6 +922,27 @@ static struct phy_device *phy_connect_fixed(struct mii_dev *bus,
 }
 #endif
 
+#ifdef CONFIG_DM_ETH_PHY
+static struct phy_device *phy_connect_dm_bound(struct mii_dev *bus,
+					       struct udevice *dev,
+					       uint mask)
+{
+	struct udevice *dm_phy_dev;
+	struct phy_device *phydev;
+
+	if (!uclass_find_device_by_phandle(UCLASS_ETH_PHY, dev,
+					   "phy-handle", &dm_phy_dev)) {
+		phydev = phy_find_by_mask(bus, mask);
+		if (phydev)
+			phydev->node = dev_ofnode(dm_phy_dev);
+
+		return phydev;
+	}
+
+	return NULL;
+}
+#endif
+
 struct phy_device *phy_connect(struct mii_dev *bus, int addr,
 			       struct udevice *dev,
 			       phy_interface_t interface)
@@ -928,8 +950,13 @@ struct phy_device *phy_connect(struct mii_dev *bus, int addr,
 	struct phy_device *phydev = NULL;
 	uint mask = (addr >= 0) ? (1 << addr) : 0xffffffff;
 
+#ifdef CONFIG_DM_ETH_PHY
+	phydev = phy_connect_dm_bound(bus, dev, mask);
+#endif
+
 #ifdef CONFIG_PHY_FIXED
-	phydev = phy_connect_fixed(bus, dev);
+	if (!phydev)
+		phydev = phy_connect_fixed(bus, dev);
 #endif
 
 #ifdef CONFIG_PHY_NCSI
-- 
2.34.1