Convert the LAN78xx driver to use the PHYlink framework for managing
PHY and MAC interactions.

Key changes include:
- Replace direct PHY operations with phylink equivalents (e.g.,
  phylink_start, phylink_stop).
- Introduce lan78xx_phylink_setup for phylink initialization and
  configuration.
- Add phylink MAC operations (lan78xx_mac_config,
  lan78xx_mac_link_down, lan78xx_mac_link_up) for managing link
  settings and flow control.
- Remove redundant and now phylink-managed functions like
  `lan78xx_link_status_change`.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v3:
- lan78xx_phy_init: drop phy_suspend()
- lan78xx_phylink_setup: use phy_interface_set_rgmii()
changes v2:
- lan78xx_mac_config: remove unused rgmii_id
- lan78xx_mac_config: PHY_INTERFACE_MODE_RGMII* variants
- lan78xx_mac_config: remove auto-speed and duplex configuration
- lan78xx_phylink_setup: set link_interface to PHY_INTERFACE_MODE_RGMII_ID
  instead of PHY_INTERFACE_MODE_NA.
- lan78xx_phy_init: use phylink_set_fixed_link() instead of allocating
  fixed PHY.
- lan78xx_configure_usb: move function values to separate variables
---
 drivers/net/usb/lan78xx.c | 559 ++++++++++++++++++++------------------
 1 file changed, 293 insertions(+), 266 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 137adf6d5b08..63b5406bfecb 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -6,6 +6,7 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
+#include <linux/phylink.h>
 #include <linux/usb.h>
 #include <linux/crc32.h>
 #include <linux/signal.h>
@@ -384,7 +385,7 @@ struct skb_data {		/* skb->cb is one of these */
 #define EVENT_RX_HALT			1
 #define EVENT_RX_MEMORY			2
 #define EVENT_STS_SPLIT			3
-#define EVENT_LINK_RESET		4
+#define EVENT_PHY_INT_ACK		4
 #define EVENT_RX_PAUSED			5
 #define EVENT_DEV_WAKING		6
 #define EVENT_DEV_ASLEEP		7
@@ -470,6 +471,9 @@ struct lan78xx_net {
 	struct statstage	stats;
 
 	struct irq_domain_data	domain_data;
+
+	struct phylink		*phylink;
+	struct phylink_config	phylink_config;
 };
 
 /* use ethtool to change the level for any given device */
@@ -1554,40 +1558,6 @@ static void lan78xx_set_multicast(struct net_device *netdev)
 	schedule_work(&pdata->set_multicast);
 }
 
-static int lan78xx_update_flowcontrol(struct lan78xx_net *dev, u8 duplex,
-				      u16 lcladv, u16 rmtadv)
-{
-	u32 flow = 0, fct_flow = 0;
-	u8 cap;
-
-	if (dev->fc_autoneg)
-		cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);
-	else
-		cap = dev->fc_request_control;
-
-	if (cap & FLOW_CTRL_TX)
-		flow |= (FLOW_CR_TX_FCEN_ | 0xFFFF);
-
-	if (cap & FLOW_CTRL_RX)
-		flow |= FLOW_CR_RX_FCEN_;
-
-	if (dev->udev->speed == USB_SPEED_SUPER)
-		fct_flow = FLOW_CTRL_THRESHOLD(FLOW_ON_SS, FLOW_OFF_SS);
-	else if (dev->udev->speed == USB_SPEED_HIGH)
-		fct_flow = FLOW_CTRL_THRESHOLD(FLOW_ON_HS, FLOW_OFF_HS);
-
-	netif_dbg(dev, link, dev->net, "rx pause %s, tx pause %s",
-		  (cap & FLOW_CTRL_RX ? "enabled" : "disabled"),
-		  (cap & FLOW_CTRL_TX ? "enabled" : "disabled"));
-
-	lan78xx_write_reg(dev, FCT_FLOW, fct_flow);
-
-	/* threshold value should be set before enabling flow */
-	lan78xx_write_reg(dev, FLOW, flow);
-
-	return 0;
-}
-
 static void lan78xx_rx_urb_submit_all(struct lan78xx_net *dev);
 
 static int lan78xx_mac_reset(struct lan78xx_net *dev)
@@ -1636,99 +1606,10 @@ static int lan78xx_mac_reset(struct lan78xx_net *dev)
 	return ret;
 }
 
-static int lan78xx_link_reset(struct lan78xx_net *dev)
+static int lan78xx_phy_int_ack(struct lan78xx_net *dev)
 {
-	struct phy_device *phydev = dev->net->phydev;
-	struct ethtool_link_ksettings ecmd;
-	int ladv, radv, ret, link;
-	u32 buf;
-
 	/* clear LAN78xx interrupt status */
-	ret = lan78xx_write_reg(dev, INT_STS, INT_STS_PHY_INT_);
-	if (unlikely(ret < 0))
-		return ret;
-
-	mutex_lock(&phydev->lock);
-	phy_read_status(phydev);
-	link = phydev->link;
-	mutex_unlock(&phydev->lock);
-
-	if (!link && dev->link_on) {
-		dev->link_on = false;
-
-		/* reset MAC */
-		ret = lan78xx_mac_reset(dev);
-		if (ret < 0)
-			return ret;
-
-		del_timer(&dev->stat_monitor);
-	} else if (link && !dev->link_on) {
-		dev->link_on = true;
-
-		phy_ethtool_ksettings_get(phydev, &ecmd);
-
-		if (dev->udev->speed == USB_SPEED_SUPER) {
-			if (ecmd.base.speed == 1000) {
-				/* disable U2 */
-				ret = lan78xx_read_reg(dev, USB_CFG1, &buf);
-				if (ret < 0)
-					return ret;
-				buf &= ~USB_CFG1_DEV_U2_INIT_EN_;
-				ret = lan78xx_write_reg(dev, USB_CFG1, buf);
-				if (ret < 0)
-					return ret;
-				/* enable U1 */
-				ret = lan78xx_read_reg(dev, USB_CFG1, &buf);
-				if (ret < 0)
-					return ret;
-				buf |= USB_CFG1_DEV_U1_INIT_EN_;
-				ret = lan78xx_write_reg(dev, USB_CFG1, buf);
-				if (ret < 0)
-					return ret;
-			} else {
-				/* enable U1 & U2 */
-				ret = lan78xx_read_reg(dev, USB_CFG1, &buf);
-				if (ret < 0)
-					return ret;
-				buf |= USB_CFG1_DEV_U2_INIT_EN_;
-				buf |= USB_CFG1_DEV_U1_INIT_EN_;
-				ret = lan78xx_write_reg(dev, USB_CFG1, buf);
-				if (ret < 0)
-					return ret;
-			}
-		}
-
-		ladv = phy_read(phydev, MII_ADVERTISE);
-		if (ladv < 0)
-			return ladv;
-
-		radv = phy_read(phydev, MII_LPA);
-		if (radv < 0)
-			return radv;
-
-		netif_dbg(dev, link, dev->net,
-			  "speed: %u duplex: %d anadv: 0x%04x anlpa: 0x%04x",
-			  ecmd.base.speed, ecmd.base.duplex, ladv, radv);
-
-		ret = lan78xx_update_flowcontrol(dev, ecmd.base.duplex, ladv,
-						 radv);
-		if (ret < 0)
-			return ret;
-
-		if (!timer_pending(&dev->stat_monitor)) {
-			dev->delta = 1;
-			mod_timer(&dev->stat_monitor,
-				  jiffies + STAT_UPDATE_TIMER);
-		}
-
-		lan78xx_rx_urb_submit_all(dev);
-
-		local_bh_disable();
-		napi_schedule(&dev->napi);
-		local_bh_enable();
-	}
-
-	return 0;
+	return lan78xx_write_reg(dev, INT_STS, INT_STS_PHY_INT_);
 }
 
 /* some work can't be done in tasklets, so we use keventd
@@ -1757,7 +1638,7 @@ static void lan78xx_status(struct lan78xx_net *dev, struct urb *urb)
 
 	if (intdata & INT_ENP_PHY_INT) {
 		netif_dbg(dev, link, dev->net, "PHY INTR: 0x%08x\n", intdata);
-		lan78xx_defer_kevent(dev, EVENT_LINK_RESET);
+		lan78xx_defer_kevent(dev, EVENT_PHY_INT_ACK);
 
 		if (dev->domain_data.phyirq > 0)
 			generic_handle_irq_safe(dev->domain_data.phyirq);
@@ -2356,26 +2237,6 @@ static void lan78xx_remove_mdio(struct lan78xx_net *dev)
 	mdiobus_free(dev->mdiobus);
 }
 
-static void lan78xx_link_status_change(struct net_device *net)
-{
-	struct lan78xx_net *dev = netdev_priv(net);
-	struct phy_device *phydev = net->phydev;
-	u32 data;
-	int ret;
-
-	ret = lan78xx_read_reg(dev, MAC_CR, &data);
-	if (ret < 0)
-		return;
-
-	if (phydev->enable_tx_lpi)
-		data |=  MAC_CR_EEE_EN_;
-	else
-		data &= ~MAC_CR_EEE_EN_;
-	lan78xx_write_reg(dev, MAC_CR, data);
-
-	phy_print_status(phydev);
-}
-
 static int irq_map(struct irq_domain *d, unsigned int irq,
 		   irq_hw_number_t hwirq)
 {
@@ -2508,27 +2369,211 @@ static void lan78xx_remove_irq_domain(struct lan78xx_net *dev)
 	dev->domain_data.irqdomain = NULL;
 }
 
-static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
+static void lan78xx_mac_config(struct phylink_config *config, unsigned int mode,
+			       const struct phylink_link_state *state)
 {
-	u32 buf;
+	struct net_device *net = to_net_dev(config->dev);
+	struct lan78xx_net *dev = netdev_priv(net);
+	u32 mac_cr = 0;
+	int ret;
+
+	/* Check if the mode is supported */
+	if (mode != MLO_AN_FIXED && mode != MLO_AN_PHY) {
+		netdev_err(net, "Unsupported negotiation mode: %u\n", mode);
+		return;
+	}
+
+	switch (state->interface) {
+	case PHY_INTERFACE_MODE_INTERNAL:
+	case PHY_INTERFACE_MODE_GMII:
+		mac_cr |= MAC_CR_GMII_EN_;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		break;
+	default:
+		netdev_warn(net, "Unsupported interface mode: %d\n",
+			    state->interface);
+		return;
+	}
+
+	ret = lan78xx_update_reg(dev, MAC_CR, MAC_CR_GMII_EN_, mac_cr);
+	if (ret < 0)
+		netdev_err(net, "Failed to config MAC with error %pe\n",
+			   ERR_PTR(ret));
+}
+
+static void lan78xx_mac_link_down(struct phylink_config *config,
+				  unsigned int mode, phy_interface_t interface)
+{
+	struct net_device *net = to_net_dev(config->dev);
+	struct lan78xx_net *dev = netdev_priv(net);
+	int ret;
+
+	/* MAC reset will not de-assert TXEN/RXEN, we need to stop them
+	 * manually before reset. TX and RX should be disabled before running
+	 * link_up sequence.
+	 */
+	ret = lan78xx_stop_tx_path(dev);
+	if (ret < 0)
+		goto link_down_fail;
+
+	ret = lan78xx_stop_rx_path(dev);
+	if (ret < 0)
+		goto link_down_fail;
+
+	/* MAC reset seems to not affect MAC configuration, no idea if it is
+	 * really needed, but it was done in previous driver version. So, leave
+	 * it here.
+	 */
+	ret = lan78xx_mac_reset(dev);
+	if (ret < 0)
+		goto link_down_fail;
+
+	return;
+
+link_down_fail:
+	netdev_err(dev->net, "Failed to set MAC down with error %pe\n",
+		   ERR_PTR(ret));
+}
+
+static int lan78xx_configure_usb(struct lan78xx_net *dev, int speed)
+{
+	u32 mask, val;
+	int ret;
+
+	/* Return early if USB speed is not SuperSpeed */
+	if (dev->udev->speed != USB_SPEED_SUPER)
+		return 0;
+
+	/* Update U1 and U2 settings based on speed */
+	if (speed != SPEED_1000) {
+		mask = USB_CFG1_DEV_U2_INIT_EN_ | USB_CFG1_DEV_U1_INIT_EN_;
+		val = USB_CFG1_DEV_U2_INIT_EN_ | USB_CFG1_DEV_U1_INIT_EN_;
+		return lan78xx_update_reg(dev, USB_CFG1, mask, val);
+	}
+
+	/* For 1000 Mbps: disable U2 and enable U1 */
+	mask = USB_CFG1_DEV_U2_INIT_EN_;
+	val = 0;
+	ret = lan78xx_update_reg(dev, USB_CFG1, mask, val);
+	if (ret < 0)
+		return ret;
+
+	mask = USB_CFG1_DEV_U1_INIT_EN_;
+	val = USB_CFG1_DEV_U1_INIT_EN_;
+	return lan78xx_update_reg(dev, USB_CFG1, mask, val);
+}
+
+static int lan78xx_configure_flowcontrol(struct lan78xx_net *dev,
+					 bool tx_pause, bool rx_pause)
+{
+	u32 flow = 0, fct_flow = 0;
 	int ret;
-	struct fixed_phy_status fphy_status = {
-		.link = 1,
-		.speed = SPEED_1000,
-		.duplex = DUPLEX_FULL,
-	};
+
+	if (tx_pause)
+		flow |= (FLOW_CR_TX_FCEN_ | 0xFFFF);
+
+	if (rx_pause)
+		flow |= FLOW_CR_RX_FCEN_;
+
+	if (dev->udev->speed == USB_SPEED_SUPER)
+		fct_flow = FLOW_CTRL_THRESHOLD(FLOW_ON_SS, FLOW_OFF_SS);
+	else if (dev->udev->speed == USB_SPEED_HIGH)
+		fct_flow = FLOW_CTRL_THRESHOLD(FLOW_ON_HS, FLOW_OFF_HS);
+
+	ret = lan78xx_write_reg(dev, FCT_FLOW, fct_flow);
+	if (ret < 0)
+		return ret;
+
+	/* threshold value should be set before enabling flow */
+	return lan78xx_write_reg(dev, FLOW, flow);
+}
+
+static void lan78xx_mac_link_up(struct phylink_config *config,
+				struct phy_device *phy,
+				unsigned int mode, phy_interface_t interface,
+				int speed, int duplex,
+				bool tx_pause, bool rx_pause)
+{
+	struct net_device *net = to_net_dev(config->dev);
+	struct lan78xx_net *dev = netdev_priv(net);
+	u32 mac_cr = 0;
+	int ret;
+
+	switch (speed) {
+	case SPEED_1000:
+		mac_cr |= MAC_CR_SPEED_1000_;
+		break;
+	case SPEED_100:
+		mac_cr |= MAC_CR_SPEED_100_;
+		break;
+	case SPEED_10:
+		mac_cr |= MAC_CR_SPEED_10_;
+		break;
+	default:
+		netdev_err(dev->net, "Unsupported speed %d\n", speed);
+		return;
+	}
+
+	if (duplex == DUPLEX_FULL)
+		mac_cr |= MAC_CR_FULL_DUPLEX_;
+
+	/* make sure TXEN and RXEN are disabled before reconfiguring MAC */
+	ret = lan78xx_update_reg(dev, MAC_CR, MAC_CR_SPEED_MASK_ |
+				 MAC_CR_FULL_DUPLEX_ | MAC_CR_EEE_EN_, mac_cr);
+	if (ret < 0)
+		goto link_up_fail;
+
+	ret = lan78xx_configure_flowcontrol(dev, tx_pause, rx_pause);
+	if (ret < 0)
+		goto link_up_fail;
+
+	ret = lan78xx_configure_usb(dev, speed);
+	if (ret < 0)
+		goto link_up_fail;
+
+	lan78xx_rx_urb_submit_all(dev);
+
+	ret = lan78xx_flush_rx_fifo(dev);
+	if (ret < 0)
+		goto link_up_fail;
+
+	ret = lan78xx_flush_tx_fifo(dev);
+	if (ret < 0)
+		goto link_up_fail;
+
+	ret = lan78xx_start_tx_path(dev);
+	if (ret < 0)
+		goto link_up_fail;
+
+	ret = lan78xx_start_rx_path(dev);
+	if (ret < 0)
+		goto link_up_fail;
+
+	return;
+link_up_fail:
+	netdev_err(dev->net, "Failed to set MAC up with error %pe\n",
+		   ERR_PTR(ret));
+}
+
+static const struct phylink_mac_ops lan78xx_phylink_mac_ops = {
+	.mac_config = lan78xx_mac_config,
+	.mac_link_down = lan78xx_mac_link_down,
+	.mac_link_up = lan78xx_mac_link_up,
+};
+
+static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
+{
 	struct phy_device *phydev;
+	int ret;
+	u32 buf;
 
 	phydev = phy_find_first(dev->mdiobus);
 	if (!phydev) {
-		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");
-		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);
-		if (IS_ERR(phydev)) {
-			netdev_err(dev->net, "No PHY/fixed_PHY found\n");
-			return NULL;
-		}
-		netdev_dbg(dev->net, "Registered FIXED PHY\n");
-		dev->interface = PHY_INTERFACE_MODE_RGMII;
+		netdev_dbg(dev->net, "PHY Not Found!! Forcing RGMII configuration\n");
 		ret = lan78xx_write_reg(dev, MAC_RGMII_ID,
 					MAC_RGMII_ID_TXC_DELAY_EN_);
 		ret = lan78xx_write_reg(dev, RGMII_TX_BYP_DLL, 0x3D00);
@@ -2541,7 +2586,7 @@ static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
 			netdev_err(dev->net, "no PHY driver found\n");
 			return NULL;
 		}
-		dev->interface = PHY_INTERFACE_MODE_RGMII_ID;
+		phydev->interface = PHY_INTERFACE_MODE_RGMII_ID;
 		/* The PHY driver is responsible to configure proper RGMII
 		 * interface delays. Disable RGMII delays on MAC side.
 		 */
@@ -2552,20 +2597,64 @@ static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
 	return phydev;
 }
 
+static int lan78xx_phylink_setup(struct lan78xx_net *dev)
+{
+	struct phylink_config *pc = &dev->phylink_config;
+	phy_interface_t link_interface;
+	struct phylink *phylink;
+
+	pc->dev = &dev->net->dev;
+	pc->type = PHYLINK_NETDEV;
+	pc->mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE | MAC_10 |
+			       MAC_100 | MAC_1000FD;
+	pc->mac_managed_pm = true;
+
+	if (dev->chipid == ID_REV_CHIP_ID_7801_) {
+		phy_interface_set_rgmii(pc->supported_interfaces);
+		link_interface = PHY_INTERFACE_MODE_RGMII_ID;
+	} else {
+		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
+			  pc->supported_interfaces);
+		link_interface = PHY_INTERFACE_MODE_INTERNAL;
+	}
+
+	phylink = phylink_create(pc, dev->net->dev.fwnode,
+				 link_interface, &lan78xx_phylink_mac_ops);
+	if (IS_ERR(phylink))
+		return PTR_ERR(phylink);
+
+	dev->phylink = phylink;
+
+	return 0;
+}
+
 static int lan78xx_phy_init(struct lan78xx_net *dev)
 {
-	__ETHTOOL_DECLARE_LINK_MODE_MASK(fc) = { 0, };
-	int ret;
-	u32 mii_adv;
 	struct phy_device *phydev;
+	int ret;
 
 	switch (dev->chipid) {
 	case ID_REV_CHIP_ID_7801_:
 		phydev = lan7801_phy_init(dev);
+		/* If no PHY found, set fixed link, probably there is no
+		 * device or some kind of different device like switch.
+		 * For example: EVB-KSZ9897-1 (KSZ9897 switch evaluation board
+		 * with LAN7801 & KSZ9031)
+		 */
 		if (!phydev) {
-			netdev_err(dev->net, "lan7801: PHY Init Failed");
-			return -EIO;
+			struct phylink_link_state state = {
+				.speed = SPEED_1000,
+				.duplex = DUPLEX_FULL,
+				.interface = PHY_INTERFACE_MODE_RGMII,
+			};
+
+			ret = phylink_set_fixed_link(dev->phylink, &state);
+			if (ret)
+				netdev_err(dev->net, "Could not set fixed link\n");
+
+			return ret;
 		}
+
 		break;
 
 	case ID_REV_CHIP_ID_7800_:
@@ -2576,7 +2665,7 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 			return -EIO;
 		}
 		phydev->is_internal = true;
-		dev->interface = PHY_INTERFACE_MODE_GMII;
+		phydev->interface = PHY_INTERFACE_MODE_GMII;
 		break;
 
 	default:
@@ -2591,37 +2680,13 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 		phydev->irq = PHY_POLL;
 	netdev_dbg(dev->net, "phydev->irq = %d\n", phydev->irq);
 
-	/* set to AUTOMDIX */
-	phydev->mdix = ETH_TP_MDI_AUTO;
-
-	ret = phy_connect_direct(dev->net, phydev,
-				 lan78xx_link_status_change,
-				 dev->interface);
+	ret = phylink_connect_phy(dev->phylink, phydev);
 	if (ret) {
 		netdev_err(dev->net, "can't attach PHY to %s\n",
 			   dev->mdiobus->id);
-		if (dev->chipid == ID_REV_CHIP_ID_7801_) {
-			if (phy_is_pseudo_fixed_link(phydev)) {
-				fixed_phy_unregister(phydev);
-				phy_device_free(phydev);
-			}
-		}
 		return -EIO;
 	}
 
-	/* MAC doesn't support 1000T Half */
-	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
-
-	/* support both flow controls */
-	dev->fc_request_control = (FLOW_CTRL_RX | FLOW_CTRL_TX);
-	linkmode_clear_bit(ETHTOOL_LINK_MODE_Pause_BIT,
-			   phydev->advertising);
-	linkmode_clear_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
-			   phydev->advertising);
-	mii_adv = (u32)mii_advertise_flowctrl(dev->fc_request_control);
-	mii_adv_to_linkmode_adv_t(fc, mii_adv);
-	linkmode_or(phydev->advertising, fc, phydev->advertising);
-
 	phy_support_eee(phydev);
 
 	if (phydev->mdio.dev.of_node) {
@@ -2646,10 +2711,6 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 		}
 	}
 
-	genphy_config_aneg(phydev);
-
-	dev->fc_autoneg = phydev->autoneg;
-
 	return 0;
 }
 
@@ -2989,7 +3050,6 @@ static int lan78xx_reset(struct lan78xx_net *dev)
 	unsigned long timeout;
 	int ret;
 	u32 buf;
-	u8 sig;
 
 	ret = lan78xx_read_reg(dev, HW_CFG, &buf);
 	if (ret < 0)
@@ -3146,22 +3206,12 @@ static int lan78xx_reset(struct lan78xx_net *dev)
 	if (ret < 0)
 		return ret;
 
+	buf &= ~(MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_);
+
 	/* LAN7801 only has RGMII mode */
-	if (dev->chipid == ID_REV_CHIP_ID_7801_) {
+	if (dev->chipid == ID_REV_CHIP_ID_7801_)
 		buf &= ~MAC_CR_GMII_EN_;
-		/* Enable Auto Duplex and Auto speed */
-		buf |= MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_;
-	}
 
-	if (dev->chipid == ID_REV_CHIP_ID_7800_ ||
-	    dev->chipid == ID_REV_CHIP_ID_7850_) {
-		ret = lan78xx_read_raw_eeprom(dev, 0, 1, &sig);
-		if (!ret && sig != EEPROM_INDICATOR) {
-			/* Implies there is no external eeprom. Set mac speed */
-			netdev_info(dev->net, "No External EEPROM. Setting MAC Speed\n");
-			buf |= MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_;
-		}
-	}
 	ret = lan78xx_write_reg(dev, MAC_CR, buf);
 	if (ret < 0)
 		return ret;
@@ -3211,9 +3261,11 @@ static int lan78xx_open(struct net_device *net)
 
 	mutex_lock(&dev->dev_mutex);
 
-	phy_start(net->phydev);
+	lan78xx_init_stats(dev);
+
+	napi_enable(&dev->napi);
 
-	netif_dbg(dev, ifup, dev->net, "phy initialised successfully");
+	set_bit(EVENT_DEV_OPEN, &dev->flags);
 
 	/* for Link Check */
 	if (dev->urb_intr) {
@@ -3225,31 +3277,9 @@ static int lan78xx_open(struct net_device *net)
 		}
 	}
 
-	ret = lan78xx_flush_rx_fifo(dev);
-	if (ret < 0)
-		goto done;
-	ret = lan78xx_flush_tx_fifo(dev);
-	if (ret < 0)
-		goto done;
-
-	ret = lan78xx_start_tx_path(dev);
-	if (ret < 0)
-		goto done;
-	ret = lan78xx_start_rx_path(dev);
-	if (ret < 0)
-		goto done;
-
-	lan78xx_init_stats(dev);
-
-	set_bit(EVENT_DEV_OPEN, &dev->flags);
+	phylink_start(dev->phylink);
 
 	netif_start_queue(net);
-
-	dev->link_on = false;
-
-	napi_enable(&dev->napi);
-
-	lan78xx_defer_kevent(dev, EVENT_LINK_RESET);
 done:
 	mutex_unlock(&dev->dev_mutex);
 
@@ -3317,12 +3347,7 @@ static int lan78xx_stop(struct net_device *net)
 		   net->stats.rx_packets, net->stats.tx_packets,
 		   net->stats.rx_errors, net->stats.tx_errors);
 
-	/* ignore errors that occur stopping the Tx and Rx data paths */
-	lan78xx_stop_tx_path(dev);
-	lan78xx_stop_rx_path(dev);
-
-	if (net->phydev)
-		phy_stop(net->phydev);
+	phylink_stop(dev->phylink);
 
 	usb_kill_urb(dev->urb_intr);
 
@@ -3332,7 +3357,7 @@ static int lan78xx_stop(struct net_device *net)
 	 */
 	clear_bit(EVENT_TX_HALT, &dev->flags);
 	clear_bit(EVENT_RX_HALT, &dev->flags);
-	clear_bit(EVENT_LINK_RESET, &dev->flags);
+	clear_bit(EVENT_PHY_INT_ACK, &dev->flags);
 	clear_bit(EVENT_STAT_UPDATE, &dev->flags);
 
 	cancel_delayed_work_sync(&dev->wq);
@@ -4256,13 +4281,13 @@ static void lan78xx_delayedwork(struct work_struct *work)
 		}
 	}
 
-	if (test_bit(EVENT_LINK_RESET, &dev->flags)) {
+	if (test_bit(EVENT_PHY_INT_ACK, &dev->flags)) {
 		int ret = 0;
 
-		clear_bit(EVENT_LINK_RESET, &dev->flags);
-		if (lan78xx_link_reset(dev) < 0) {
-			netdev_info(dev->net, "link reset failed (%d)\n",
-				    ret);
+		clear_bit(EVENT_PHY_INT_ACK, &dev->flags);
+		if (lan78xx_phy_int_ack(dev) < 0) {
+			netdev_info(dev->net, "PHY INT ack failed (%pe)\n",
+				    ERR_PTR(ret));
 		}
 	}
 
@@ -4337,32 +4362,29 @@ static void lan78xx_disconnect(struct usb_interface *intf)
 	struct lan78xx_net *dev;
 	struct usb_device *udev;
 	struct net_device *net;
-	struct phy_device *phydev;
 
 	dev = usb_get_intfdata(intf);
 	usb_set_intfdata(intf, NULL);
 	if (!dev)
 		return;
 
-	netif_napi_del(&dev->napi);
-
 	udev = interface_to_usbdev(intf);
 	net = dev->net;
 
+	rtnl_lock();
+	phylink_stop(dev->phylink);
+	phylink_disconnect_phy(dev->phylink);
+	rtnl_unlock();
+
+	netif_napi_del(&dev->napi);
+
 	unregister_netdev(net);
 
 	timer_shutdown_sync(&dev->stat_monitor);
 	set_bit(EVENT_DEV_DISCONNECT, &dev->flags);
 	cancel_delayed_work_sync(&dev->wq);
 
-	phydev = net->phydev;
-
-	phy_disconnect(net->phydev);
-
-	if (phy_is_pseudo_fixed_link(phydev)) {
-		fixed_phy_unregister(phydev);
-		phy_device_free(phydev);
-	}
+	phylink_destroy(dev->phylink);
 
 	usb_scuttle_anchored_urbs(&dev->deferred);
 
@@ -4446,7 +4468,6 @@ static int lan78xx_probe(struct usb_interface *intf,
 		goto out1;
 	}
 
-	/* netdev_printk() needs this */
 	SET_NETDEV_DEV(netdev, &intf->dev);
 
 	dev = netdev_priv(netdev);
@@ -4558,14 +4579,18 @@ static int lan78xx_probe(struct usb_interface *intf,
 	/* driver requires remote-wakeup capability during autosuspend. */
 	intf->needs_remote_wakeup = 1;
 
-	ret = lan78xx_phy_init(dev);
+	ret = lan78xx_phylink_setup(dev);
 	if (ret < 0)
 		goto free_urbs;
 
+	ret = lan78xx_phy_init(dev);
+	if (ret < 0)
+		goto destroy_phylink;
+
 	ret = register_netdev(netdev);
 	if (ret != 0) {
 		netif_err(dev, probe, netdev, "couldn't register the device\n");
-		goto out8;
+		goto disconnect_phy;
 	}
 
 	usb_set_intfdata(intf, dev);
@@ -4580,8 +4605,10 @@ static int lan78xx_probe(struct usb_interface *intf,
 
 	return 0;
 
-out8:
-	phy_disconnect(netdev->phydev);
+disconnect_phy:
+	phylink_disconnect_phy(dev->phylink);
+destroy_phylink:
+	phylink_destroy(dev->phylink);
 free_urbs:
 	usb_free_urb(dev->urb_intr);
 out5:
@@ -5143,7 +5170,7 @@ static int lan78xx_reset_resume(struct usb_interface *intf)
 	if (ret < 0)
 		return ret;
 
-	phy_start(dev->net->phydev);
+	phylink_start(dev->phylink);
 
 	ret = lan78xx_resume(intf);
 
-- 
2.39.5

On Mon, Mar 10, 2025 at 12:57:31PM +0100, Oleksij Rempel wrote:

...

> +static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
> +{
>  	struct phy_device *phydev;
> +	int ret;

nit: not strictly related to this patch as the problem already existed,
     but ret is set but otherwise unused in this function. Perhaps
     it can be removed at some point?

     Flagged by W=1 builds.

> +	u32 buf;
>  
>  	phydev = phy_find_first(dev->mdiobus);
>  	if (!phydev) {
> -		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");
> -		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);
> -		if (IS_ERR(phydev)) {
> -			netdev_err(dev->net, "No PHY/fixed_PHY found\n");
> -			return NULL;
> -		}
> -		netdev_dbg(dev->net, "Registered FIXED PHY\n");
> -		dev->interface = PHY_INTERFACE_MODE_RGMII;
> +		netdev_dbg(dev->net, "PHY Not Found!! Forcing RGMII configuration\n");
>  		ret = lan78xx_write_reg(dev, MAC_RGMII_ID,
>  					MAC_RGMII_ID_TXC_DELAY_EN_);
>  		ret = lan78xx_write_reg(dev, RGMII_TX_BYP_DLL, 0x3D00);

...

> @@ -4256,13 +4281,13 @@ static void lan78xx_delayedwork(struct work_struct *work)
>  		}
>  	}
>  
> -	if (test_bit(EVENT_LINK_RESET, &dev->flags)) {
> +	if (test_bit(EVENT_PHY_INT_ACK, &dev->flags)) {
>  		int ret = 0;
>  
> -		clear_bit(EVENT_LINK_RESET, &dev->flags);
> -		if (lan78xx_link_reset(dev) < 0) {
> -			netdev_info(dev->net, "link reset failed (%d)\n",
> -				    ret);
> +		clear_bit(EVENT_PHY_INT_ACK, &dev->flags);
> +		if (lan78xx_phy_int_ack(dev) < 0) {
> +			netdev_info(dev->net, "PHY INT ack failed (%pe)\n",
> +				    ERR_PTR(ret));

nit: ret is always 0 here. So I'm unsure both why it is useful to include
     in the error message, and why ERR_PTR() is being used.

     Flagged by Smatch.

>  		}
>  	}
>  

...

On Mon, Mar 17, 2025 at 03:36:11PM +0000, Simon Horman wrote:
> On Mon, Mar 10, 2025 at 12:57:31PM +0100, Oleksij Rempel wrote:
> 
> ...
> 
> > +static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)
> > +{
> >  	struct phy_device *phydev;
> > +	int ret;
> 
> nit: not strictly related to this patch as the problem already existed,
>      but ret is set but otherwise unused in this function. Perhaps
>      it can be removed at some point?
> 
>      Flagged by W=1 builds.

Ack. This is addresses in 3. patch

> > +	u32 buf;
> >  
> >  	phydev = phy_find_first(dev->mdiobus);
> >  	if (!phydev) {
> > -		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");
> > -		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);
> > -		if (IS_ERR(phydev)) {
> > -			netdev_err(dev->net, "No PHY/fixed_PHY found\n");
> > -			return NULL;
> > -		}
> > -		netdev_dbg(dev->net, "Registered FIXED PHY\n");
> > -		dev->interface = PHY_INTERFACE_MODE_RGMII;
> > +		netdev_dbg(dev->net, "PHY Not Found!! Forcing RGMII configuration\n");
> >  		ret = lan78xx_write_reg(dev, MAC_RGMII_ID,
> >  					MAC_RGMII_ID_TXC_DELAY_EN_);
> >  		ret = lan78xx_write_reg(dev, RGMII_TX_BYP_DLL, 0x3D00);
> 
> ...
> 
> > @@ -4256,13 +4281,13 @@ static void lan78xx_delayedwork(struct work_struct *work)
> >  		}
> >  	}
> >  
> > -	if (test_bit(EVENT_LINK_RESET, &dev->flags)) {
> > +	if (test_bit(EVENT_PHY_INT_ACK, &dev->flags)) {
> >  		int ret = 0;
> >  
> > -		clear_bit(EVENT_LINK_RESET, &dev->flags);
> > -		if (lan78xx_link_reset(dev) < 0) {
> > -			netdev_info(dev->net, "link reset failed (%d)\n",
> > -				    ret);
> > +		clear_bit(EVENT_PHY_INT_ACK, &dev->flags);
> > +		if (lan78xx_phy_int_ack(dev) < 0) {
> > +			netdev_info(dev->net, "PHY INT ack failed (%pe)\n",
> > +				    ERR_PTR(ret));
> 
> nit: ret is always 0 here. So I'm unsure both why it is useful to include
>      in the error message, and why ERR_PTR() is being used.
> 
>      Flagged by Smatch.

Thank you, i'll take a look on it.

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Hi Oleksij,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Oleksij-Rempel/net-usb-lan78xx-Convert-to-PHYlink-for-improved-PHY-and-MAC-management/20250310-200116
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250310115737.784047-2-o.rempel%40pengutronix.de
patch subject: [PATCH net-next v3 1/7] net: usb: lan78xx: Convert to PHYlink for improved PHY and MAC management
config: i386-randconfig-006-20250315 (https://download.01.org/0day-ci/archive/20250315/202503151113.AFty2HdH-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250315/202503151113.AFty2HdH-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503151113.AFty2HdH-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_phy_init':
>> drivers/net/usb/lan78xx.c:2683: undefined reference to `phylink_connect_phy'
>> ld: drivers/net/usb/lan78xx.c:2651: undefined reference to `phylink_set_fixed_link'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_open':
>> drivers/net/usb/lan78xx.c:3280: undefined reference to `phylink_start'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_stop':
>> drivers/net/usb/lan78xx.c:3350: undefined reference to `phylink_stop'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_disconnect':
   drivers/net/usb/lan78xx.c:4375: undefined reference to `phylink_stop'
>> ld: drivers/net/usb/lan78xx.c:4376: undefined reference to `phylink_disconnect_phy'
>> ld: drivers/net/usb/lan78xx.c:4387: undefined reference to `phylink_destroy'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_phylink_setup':
>> drivers/net/usb/lan78xx.c:2621: undefined reference to `phylink_create'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_probe':
>> drivers/net/usb/lan78xx.c:4609: undefined reference to `phylink_disconnect_phy'
   ld: drivers/net/usb/lan78xx.c:4611: undefined reference to `phylink_destroy'
   ld: drivers/net/usb/lan78xx.o: in function `lan78xx_reset_resume':
   drivers/net/usb/lan78xx.c:5173: undefined reference to `phylink_start'


vim +2683 drivers/net/usb/lan78xx.c

  2599	
  2600	static int lan78xx_phylink_setup(struct lan78xx_net *dev)
  2601	{
  2602		struct phylink_config *pc = &dev->phylink_config;
  2603		phy_interface_t link_interface;
  2604		struct phylink *phylink;
  2605	
  2606		pc->dev = &dev->net->dev;
  2607		pc->type = PHYLINK_NETDEV;
  2608		pc->mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE | MAC_10 |
  2609				       MAC_100 | MAC_1000FD;
  2610		pc->mac_managed_pm = true;
  2611	
  2612		if (dev->chipid == ID_REV_CHIP_ID_7801_) {
  2613			phy_interface_set_rgmii(pc->supported_interfaces);
  2614			link_interface = PHY_INTERFACE_MODE_RGMII_ID;
  2615		} else {
  2616			__set_bit(PHY_INTERFACE_MODE_INTERNAL,
  2617				  pc->supported_interfaces);
  2618			link_interface = PHY_INTERFACE_MODE_INTERNAL;
  2619		}
  2620	
> 2621		phylink = phylink_create(pc, dev->net->dev.fwnode,
  2622					 link_interface, &lan78xx_phylink_mac_ops);
  2623		if (IS_ERR(phylink))
  2624			return PTR_ERR(phylink);
  2625	
  2626		dev->phylink = phylink;
  2627	
  2628		return 0;
  2629	}
  2630	
  2631	static int lan78xx_phy_init(struct lan78xx_net *dev)
  2632	{
  2633		struct phy_device *phydev;
  2634		int ret;
  2635	
  2636		switch (dev->chipid) {
  2637		case ID_REV_CHIP_ID_7801_:
  2638			phydev = lan7801_phy_init(dev);
  2639			/* If no PHY found, set fixed link, probably there is no
  2640			 * device or some kind of different device like switch.
  2641			 * For example: EVB-KSZ9897-1 (KSZ9897 switch evaluation board
  2642			 * with LAN7801 & KSZ9031)
  2643			 */
  2644			if (!phydev) {
  2645				struct phylink_link_state state = {
  2646					.speed = SPEED_1000,
  2647					.duplex = DUPLEX_FULL,
  2648					.interface = PHY_INTERFACE_MODE_RGMII,
  2649				};
  2650	
> 2651				ret = phylink_set_fixed_link(dev->phylink, &state);
  2652				if (ret)
  2653					netdev_err(dev->net, "Could not set fixed link\n");
  2654	
  2655				return ret;
  2656			}
  2657	
  2658			break;
  2659	
  2660		case ID_REV_CHIP_ID_7800_:
  2661		case ID_REV_CHIP_ID_7850_:
  2662			phydev = phy_find_first(dev->mdiobus);
  2663			if (!phydev) {
  2664				netdev_err(dev->net, "no PHY found\n");
  2665				return -EIO;
  2666			}
  2667			phydev->is_internal = true;
  2668			phydev->interface = PHY_INTERFACE_MODE_GMII;
  2669			break;
  2670	
  2671		default:
  2672			netdev_err(dev->net, "Unknown CHIP ID found\n");
  2673			return -EIO;
  2674		}
  2675	
  2676		/* if phyirq is not set, use polling mode in phylib */
  2677		if (dev->domain_data.phyirq > 0)
  2678			phydev->irq = dev->domain_data.phyirq;
  2679		else
  2680			phydev->irq = PHY_POLL;
  2681		netdev_dbg(dev->net, "phydev->irq = %d\n", phydev->irq);
  2682	
> 2683		ret = phylink_connect_phy(dev->phylink, phydev);
  2684		if (ret) {
  2685			netdev_err(dev->net, "can't attach PHY to %s\n",
  2686				   dev->mdiobus->id);
  2687			return -EIO;
  2688		}
  2689	
  2690		phy_support_eee(phydev);
  2691	
  2692		if (phydev->mdio.dev.of_node) {
  2693			u32 reg;
  2694			int len;
  2695	
  2696			len = of_property_count_elems_of_size(phydev->mdio.dev.of_node,
  2697							      "microchip,led-modes",
  2698							      sizeof(u32));
  2699			if (len >= 0) {
  2700				/* Ensure the appropriate LEDs are enabled */
  2701				lan78xx_read_reg(dev, HW_CFG, &reg);
  2702				reg &= ~(HW_CFG_LED0_EN_ |
  2703					 HW_CFG_LED1_EN_ |
  2704					 HW_CFG_LED2_EN_ |
  2705					 HW_CFG_LED3_EN_);
  2706				reg |= (len > 0) * HW_CFG_LED0_EN_ |
  2707					(len > 1) * HW_CFG_LED1_EN_ |
  2708					(len > 2) * HW_CFG_LED2_EN_ |
  2709					(len > 3) * HW_CFG_LED3_EN_;
  2710				lan78xx_write_reg(dev, HW_CFG, reg);
  2711			}
  2712		}
  2713	
  2714		return 0;
  2715	}
  2716	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki