Merge branch 'net-phy-remove-probe_capabilities'

Michael Walle says:

====================
net: phy: Remove probe_capabilities

With all the drivers which used .probe_capabilities converted to the
new c45 MDIO access methods, we can now decide based upon these whether
a bus driver supports c45 and we can get rid of the not widely used
probe_capabilites.

Unfortunately, due to a now broader support of c45 scans, this will
trigger a bug on some boards with a (c22-only) Micrel PHY. These PHYs
don't ignore c45 accesses correctly, thinking they are addressed
themselves and distrupt the MDIO access. To avoid this, a blacklist
for c45 scans is introduced.
====================

Link: https://lore.kernel.org/r/20230116-net-next-remove-probe-capabilities-v2-0-15513b05e1f4@walle.cc
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

11 files changed, 140 insertions, 82 deletions

diff --git a/drivers/net/ethernet/adi/adin1110.c b/drivers/net/ethernet/adi/adin1110.c
index 0805f249fff2..25f55756681d 100644
--- a/drivers/net/ethernet/adi/adin1110.c
+++ b/drivers/net/ethernet/adi/adin1110.c
@@ -523,7 +523,6 @@ static int adin1110_register_mdiobus(struct adin1110_priv *priv,
 	mii_bus->priv = priv;
 	mii_bus->parent = dev;
 	mii_bus->phy_mask = ~((u32)GENMASK(2, 0));
-	mii_bus->probe_capabilities = MDIOBUS_C22;
 	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
 
 	ret = devm_mdiobus_register(dev, mii_bus);
diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
index 8b5a4cd8ff08..a13b4ba4d6e1 100644
--- a/drivers/net/ethernet/freescale/xgmac_mdio.c
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -397,7 +397,6 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	bus->read_c45 = xgmac_mdio_read_c45;
 	bus->write_c45 = xgmac_mdio_write_c45;
 	bus->parent = &pdev->dev;
-	bus->probe_capabilities = MDIOBUS_C22_C45;
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res->start);
 
 	priv = bus->priv;
diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
index cf456d62677f..87fff539d39d 100644
--- a/drivers/net/ethernet/marvell/pxa168_eth.c
+++ b/drivers/net/ethernet/marvell/pxa168_eth.c
@@ -965,7 +965,7 @@ static int pxa168_init_phy(struct net_device *dev)
 	if (dev->phydev)
 		return 0;
 
-	phy = mdiobus_scan(pep->smi_bus, pep->phy_addr);
+	phy = mdiobus_scan_c22(pep->smi_bus, pep->phy_addr);
 	if (IS_ERR(phy))
 		return PTR_ERR(phy);
 
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 75bbb1e7766c..801deac58bf7 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -814,7 +814,6 @@ static int mtk_mdio_init(struct mtk_eth *eth)
 	eth->mii_bus->write = mtk_mdio_write_c22;
 	eth->mii_bus->read_c45 = mtk_mdio_read_c45;
 	eth->mii_bus->write_c45 = mtk_mdio_write_c45;
-	eth->mii_bus->probe_capabilities = MDIOBUS_C22_C45;
 	eth->mii_bus->priv = eth;
 	eth->mii_bus->parent = eth->dev;
 
diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index b5add1c5fa06..7e0871b631e4 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -3302,7 +3302,6 @@ static int lan743x_mdiobus_init(struct lan743x_adapter *adapter)
 			lan743x_csr_write(adapter, SGMII_CTL, sgmii_ctl);
 			netif_dbg(adapter, drv, adapter->netdev,
 				  "SGMII operation\n");
-			adapter->mdiobus->probe_capabilities = MDIOBUS_C22_C45;
 			adapter->mdiobus->read = lan743x_mdiobus_read_c22;
 			adapter->mdiobus->write = lan743x_mdiobus_write_c22;
 			adapter->mdiobus->read_c45 = lan743x_mdiobus_read_c45;
@@ -3318,7 +3317,6 @@ static int lan743x_mdiobus_init(struct lan743x_adapter *adapter)
 			netif_dbg(adapter, drv, adapter->netdev,
 				  "RGMII operation\n");
 			// Only C22 support when RGMII I/F
-			adapter->mdiobus->probe_capabilities = MDIOBUS_C22;
 			adapter->mdiobus->read = lan743x_mdiobus_read_c22;
 			adapter->mdiobus->write = lan743x_mdiobus_write_c22;
 			adapter->mdiobus->name = "lan743x-mdiobus";
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index d2cb22f49ce5..21aaa2730ac8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -553,9 +553,6 @@ int stmmac_mdio_register(struct net_device *ndev)
 
 	new_bus->name = "stmmac";
 
-	if (priv->plat->has_gmac4)
-		new_bus->probe_capabilities = MDIOBUS_C22_C45;
-
 	if (priv->plat->has_xgmac) {
 		new_bus->read = &stmmac_xgmac2_mdio_read_c22;
 		new_bus->write = &stmmac_xgmac2_mdio_write_c22;
diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
index 2f4bbda5e56c..c727103c8b05 100644
--- a/drivers/net/mdio/mdio-aspeed.c
+++ b/drivers/net/mdio/mdio-aspeed.c
@@ -164,7 +164,6 @@ static int aspeed_mdio_probe(struct platform_device *pdev)
 	bus->write = aspeed_mdio_write_c22;
 	bus->read_c45 = aspeed_mdio_read_c45;
 	bus->write_c45 = aspeed_mdio_write_c45;
-	bus->probe_capabilities = MDIOBUS_C22_C45;
 
 	rc = of_mdiobus_register(bus, pdev->dev.of_node);
 	if (rc) {
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 902e1c88ef58..5b2f48c09a6a 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -19,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/micrel_phy.h>
 #include <linux/mii.h>
 #include <linux/mm.h>
 #include <linux/module.h>
@@ -506,6 +507,126 @@ static int mdiobus_create_device(struct mii_bus *bus,
 	return ret;
 }
 
+static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
+{
+	struct phy_device *phydev = ERR_PTR(-ENODEV);
+	int err;
+
+	phydev = get_phy_device(bus, addr, c45);
+	if (IS_ERR(phydev))
+		return phydev;
+
+	/* For DT, see if the auto-probed phy has a corresponding child
+	 * in the bus node, and set the of_node pointer in this case.
+	 */
+	of_mdiobus_link_mdiodev(bus, &phydev->mdio);
+
+	err = phy_device_register(phydev);
+	if (err) {
+		phy_device_free(phydev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return phydev;
+}
+
+/**
+ * mdiobus_scan_c22 - scan one address on a bus for C22 MDIO devices.
+ * @bus: mii_bus to scan
+ * @addr: address on bus to scan
+ *
+ * This function scans one address on the MDIO bus, looking for
+ * devices which can be identified using a vendor/product ID in
+ * registers 2 and 3. Not all MDIO devices have such registers, but
+ * PHY devices typically do. Hence this function assumes anything
+ * found is a PHY, or can be treated as a PHY. Other MDIO devices,
+ * such as switches, will probably not be found during the scan.
+ */
+struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr)
+{
+	return mdiobus_scan(bus, addr, false);
+}
+EXPORT_SYMBOL(mdiobus_scan_c22);
+
+/**
+ * mdiobus_scan_c45 - scan one address on a bus for C45 MDIO devices.
+ * @bus: mii_bus to scan
+ * @addr: address on bus to scan
+ *
+ * This function scans one address on the MDIO bus, looking for
+ * devices which can be identified using a vendor/product ID in
+ * registers 2 and 3. Not all MDIO devices have such registers, but
+ * PHY devices typically do. Hence this function assumes anything
+ * found is a PHY, or can be treated as a PHY. Other MDIO devices,
+ * such as switches, will probably not be found during the scan.
+ */
+static struct phy_device *mdiobus_scan_c45(struct mii_bus *bus, int addr)
+{
+	return mdiobus_scan(bus, addr, true);
+}
+
+static int mdiobus_scan_bus_c22(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		if ((bus->phy_mask & BIT(i)) == 0) {
+			struct phy_device *phydev;
+
+			phydev = mdiobus_scan_c22(bus, i);
+			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
+				return PTR_ERR(phydev);
+		}
+	}
+	return 0;
+}
+
+static int mdiobus_scan_bus_c45(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		if ((bus->phy_mask & BIT(i)) == 0) {
+			struct phy_device *phydev;
+
+			/* Don't scan C45 if we already have a C22 device */
+			if (bus->mdio_map[i])
+				continue;
+
+			phydev = mdiobus_scan_c45(bus, i);
+			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
+				return PTR_ERR(phydev);
+		}
+	}
+	return 0;
+}
+
+/* There are some C22 PHYs which do bad things when where is a C45
+ * transaction on the bus, like accepting a read themselves, and
+ * stomping over the true devices reply, to performing a write to
+ * themselves which was intended for another device. Now that C22
+ * devices have been found, see if any of them are bad for C45, and if we
+ * should skip the C45 scan.
+ */
+static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		struct phy_device *phydev;
+		u32 oui;
+
+		phydev = mdiobus_get_phy(bus, i);
+		if (!phydev)
+			continue;
+		oui = phydev->phy_id >> 10;
+
+		if (oui == MICREL_OUI)
+			return true;
+	}
+	return false;
+}
+
 /**
  * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  * @bus: target mii_bus
@@ -523,8 +644,9 @@ static int mdiobus_create_device(struct mii_bus *bus,
 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 {
 	struct mdio_device *mdiodev;
-	int i, err;
 	struct gpio_desc *gpiod;
+	bool prevent_c45_scan;
+	int i, err;
 
 	if (!bus || !bus->name)
 		return -EINVAL;
@@ -589,16 +711,18 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 			goto error_reset_gpiod;
 	}
 
-	for (i = 0; i < PHY_MAX_ADDR; i++) {
-		if ((bus->phy_mask & BIT(i)) == 0) {
-			struct phy_device *phydev;
+	if (bus->read) {
+		err = mdiobus_scan_bus_c22(bus);
+		if (err)
+			goto error;
+	}
 
-			phydev = mdiobus_scan(bus, i);
-			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
-				err = PTR_ERR(phydev);
-				goto error;
-			}
-		}
+	prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
+
+	if (!prevent_c45_scan && bus->read_c45) {
+		err = mdiobus_scan_bus_c45(bus);
+		if (err)
+			goto error;
 	}
 
 	mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
@@ -608,7 +732,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 	return 0;
 
 error:
-	while (--i >= 0) {
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
 		mdiodev = bus->mdio_map[i];
 		if (!mdiodev)
 			continue;
@@ -679,57 +803,6 @@ void mdiobus_free(struct mii_bus *bus)
 }
 EXPORT_SYMBOL(mdiobus_free);
 
-/**
- * mdiobus_scan - scan a bus for MDIO devices.
- * @bus: mii_bus to scan
- * @addr: address on bus to scan
- *
- * This function scans the MDIO bus, looking for devices which can be
- * identified using a vendor/product ID in registers 2 and 3. Not all
- * MDIO devices have such registers, but PHY devices typically
- * do. Hence this function assumes anything found is a PHY, or can be
- * treated as a PHY. Other MDIO devices, such as switches, will
- * probably not be found during the scan.
- */
-struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
-{
-	struct phy_device *phydev = ERR_PTR(-ENODEV);
-	int err;
-
-	switch (bus->probe_capabilities) {
-	case MDIOBUS_NO_CAP:
-	case MDIOBUS_C22:
-		phydev = get_phy_device(bus, addr, false);
-		break;
-	case MDIOBUS_C45:
-		phydev = get_phy_device(bus, addr, true);
-		break;
-	case MDIOBUS_C22_C45:
-		phydev = get_phy_device(bus, addr, false);
-		if (IS_ERR(phydev))
-			phydev = get_phy_device(bus, addr, true);
-		break;
-	}
-
-	if (IS_ERR(phydev))
-		return phydev;
-
-	/*
-	 * For DT, see if the auto-probed phy has a correspoding child
-	 * in the bus node, and set the of_node pointer in this case.
-	 */
-	of_mdiobus_link_mdiodev(bus, &phydev->mdio);
-
-	err = phy_device_register(phydev);
-	if (err) {
-		phy_device_free(phydev);
-		return ERR_PTR(-ENODEV);
-	}
-
-	return phydev;
-}
-EXPORT_SYMBOL(mdiobus_scan);
-
 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
 {
 	preempt_disable();
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 0d371a0a49f2..9ba8f973f26f 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -946,7 +946,7 @@ struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45)
 	 * probe with C45 to see if we're able to get a valid PHY ID in the C45
 	 * space, if successful, create the C45 PHY device.
 	 */
-	if (!is_c45 && phy_id == 0 && bus->probe_capabilities >= MDIOBUS_C45) {
+	if (!is_c45 && phy_id == 0 && bus->read_c45) {
 		r = get_phy_c45_ids(bus, addr, &c45_ids);
 		if (!r)
 			return phy_device_create(bus, addr, phy_id,
diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
index 1f7c33b2f5a3..771e050883db 100644
--- a/include/linux/micrel_phy.h
+++ b/include/linux/micrel_phy.h
@@ -8,6 +8,8 @@
 #ifndef _MICREL_PHY_H
 #define _MICREL_PHY_H
 
+#define MICREL_OUI		0x0885
+
 #define MICREL_PHY_ID_MASK	0x00fffff0
 
 #define PHY_ID_KSZ8873MLL	0x000e7237
diff --git a/include/linux/phy.h b/include/linux/phy.h
index b3cf1e08e880..fbeba4fee8d4 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -419,14 +419,6 @@ struct mii_bus {
 	/** @reset_gpiod: Reset GPIO descriptor pointer */
 	struct gpio_desc *reset_gpiod;
 
-	/** @probe_capabilities: bus capabilities, used for probing */
-	enum {
-		MDIOBUS_NO_CAP = 0,
-		MDIOBUS_C22,
-		MDIOBUS_C45,
-		MDIOBUS_C22_C45,
-	} probe_capabilities;
-
 	/** @shared_lock: protect access to the shared element */
 	struct mutex shared_lock;
 
@@ -464,7 +456,7 @@ static inline struct mii_bus *devm_mdiobus_alloc(struct device *dev)
 }
 
 struct mii_bus *mdio_find_bus(const char *mdio_name);
-struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
+struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr);
 
 #define PHY_INTERRUPT_DISABLED	false
 #define PHY_INTERRUPT_ENABLED	true