1 files changed, 285 insertions, 74 deletions

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 4514d35ef4c4..232bbd79a4de 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -230,7 +230,9 @@ static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf)
 	int i;
 	unsigned long gpio_bits = dev->driver_info->data;
 
-	usbnet_get_endpoints(dev,intf);
+	ret = usbnet_get_endpoints(dev, intf);
+	if (ret)
+		goto out;
 
 	/* Toggle the GPIOs in a manufacturer/model specific way */
 	for (i = 2; i >= 0; i--) {
@@ -303,6 +305,24 @@ static int ax88772_ethtool_get_sset_count(struct net_device *ndev, int sset)
 	}
 }
 
+static void ax88772_ethtool_get_pauseparam(struct net_device *ndev,
+					  struct ethtool_pauseparam *pause)
+{
+	struct usbnet *dev = netdev_priv(ndev);
+	struct asix_common_private *priv = dev->driver_priv;
+
+	phylink_ethtool_get_pauseparam(priv->phylink, pause);
+}
+
+static int ax88772_ethtool_set_pauseparam(struct net_device *ndev,
+					 struct ethtool_pauseparam *pause)
+{
+	struct usbnet *dev = netdev_priv(ndev);
+	struct asix_common_private *priv = dev->driver_priv;
+
+	return phylink_ethtool_set_pauseparam(priv->phylink, pause);
+}
+
 static const struct ethtool_ops ax88772_ethtool_ops = {
 	.get_drvinfo		= asix_get_drvinfo,
 	.get_link		= usbnet_get_link,
@@ -319,6 +339,8 @@ static const struct ethtool_ops ax88772_ethtool_ops = {
 	.self_test		= net_selftest,
 	.get_strings		= ax88772_ethtool_get_strings,
 	.get_sset_count		= ax88772_ethtool_get_sset_count,
+	.get_pauseparam		= ax88772_ethtool_get_pauseparam,
+	.set_pauseparam		= ax88772_ethtool_set_pauseparam,
 };
 
 static int ax88772_reset(struct usbnet *dev)
@@ -343,7 +365,7 @@ static int ax88772_reset(struct usbnet *dev)
 	if (ret < 0)
 		goto out;
 
-	phy_start(priv->phydev);
+	phylink_start(priv->phylink);
 
 	return 0;
 
@@ -450,7 +472,6 @@ static int ax88772a_hw_reset(struct usbnet *dev, int in_pm)
 	struct asix_data *data = (struct asix_data *)&dev->data;
 	struct asix_common_private *priv = dev->driver_priv;
 	u16 rx_ctl, phy14h, phy15h, phy16h;
-	u8 chipcode = 0;
 	int ret;
 
 	ret = asix_write_gpio(dev, AX_GPIO_RSE, 5, in_pm);
@@ -493,12 +514,7 @@ static int ax88772a_hw_reset(struct usbnet *dev, int in_pm)
 		goto out;
 	}
 
-	ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0,
-			    0, 1, &chipcode, in_pm);
-	if (ret < 0)
-		goto out;
-
-	if ((chipcode & AX_CHIPCODE_MASK) == AX_AX88772B_CHIPCODE) {
+	if (priv->chipcode == AX_AX88772B_CHIPCODE) {
 		ret = asix_write_cmd(dev, AX_QCTCTRL, 0x8000, 0x8001,
 				     0, NULL, in_pm);
 		if (ret < 0) {
@@ -506,7 +522,7 @@ static int ax88772a_hw_reset(struct usbnet *dev, int in_pm)
 				   ret);
 			goto out;
 		}
-	} else if ((chipcode & AX_CHIPCODE_MASK) == AX_AX88772A_CHIPCODE) {
+	} else if (priv->chipcode == AX_AX88772A_CHIPCODE) {
 		/* Check if the PHY registers have default settings */
 		phy14h = asix_mdio_read_nopm(dev->net, dev->mii.phy_id,
 					     AX88772A_PHY14H);
@@ -596,8 +612,11 @@ static void ax88772_suspend(struct usbnet *dev)
 	struct asix_common_private *priv = dev->driver_priv;
 	u16 medium;
 
-	if (netif_running(dev->net))
-		phy_stop(priv->phydev);
+	if (netif_running(dev->net)) {
+		rtnl_lock();
+		phylink_suspend(priv->phylink, false);
+		rtnl_unlock();
+	}
 
 	/* Stop MAC operation */
 	medium = asix_read_medium_status(dev, 1);
@@ -608,6 +627,21 @@ static void ax88772_suspend(struct usbnet *dev)
 		   asix_read_medium_status(dev, 1));
 }
 
+/* Notes on PM callbacks and locking context:
+ *
+ * - asix_suspend()/asix_resume() are invoked for both runtime PM and
+ *   system-wide suspend/resume. For struct usb_driver the ->resume()
+ *   callback does not receive pm_message_t, so the resume type cannot
+ *   be distinguished here.
+ *
+ * - The MAC driver must hold RTNL when calling phylink interfaces such as
+ *   phylink_suspend()/resume(). Those calls will also perform MDIO I/O.
+ *
+ * - Taking RTNL and doing MDIO from a runtime-PM resume callback (while
+ *   the USB PM lock is held) is fragile. Since autosuspend brings no
+ *   measurable power saving here, we block it by holding a PM usage
+ *   reference in ax88772_bind().
+ */
 static int asix_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct usbnet *dev = usb_get_intfdata(intf);
@@ -625,25 +659,14 @@ static void ax88772_resume(struct usbnet *dev)
 	int i;
 
 	for (i = 0; i < 3; i++)
-		if (!ax88772_hw_reset(dev, 1))
+		if (!priv->reset(dev, 1))
 			break;
 
-	if (netif_running(dev->net))
-		phy_start(priv->phydev);
-}
-
-static void ax88772a_resume(struct usbnet *dev)
-{
-	struct asix_common_private *priv = dev->driver_priv;
-	int i;
-
-	for (i = 0; i < 3; i++) {
-		if (!ax88772a_hw_reset(dev, 1))
-			break;
+	if (netif_running(dev->net)) {
+		rtnl_lock();
+		phylink_resume(priv->phylink);
+		rtnl_unlock();
 	}
-
-	if (netif_running(dev->net))
-		phy_start(priv->phydev);
 }
 
 static int asix_resume(struct usb_interface *intf)
@@ -660,8 +683,9 @@ static int asix_resume(struct usb_interface *intf)
 static int ax88772_init_mdio(struct usbnet *dev)
 {
 	struct asix_common_private *priv = dev->driver_priv;
+	int ret;
 
-	priv->mdio = devm_mdiobus_alloc(&dev->udev->dev);
+	priv->mdio = mdiobus_alloc();
 	if (!priv->mdio)
 		return -ENOMEM;
 
@@ -669,11 +693,25 @@ static int ax88772_init_mdio(struct usbnet *dev)
 	priv->mdio->read = &asix_mdio_bus_read;
 	priv->mdio->write = &asix_mdio_bus_write;
 	priv->mdio->name = "Asix MDIO Bus";
+	priv->mdio->phy_mask = ~(BIT(priv->phy_addr & 0x1f) | BIT(AX_EMBD_PHY_ADDR));
 	/* mii bus name is usb-<usb bus number>-<usb device number> */
 	snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "usb-%03d:%03d",
 		 dev->udev->bus->busnum, dev->udev->devnum);
 
-	return devm_mdiobus_register(&dev->udev->dev, priv->mdio);
+	ret = mdiobus_register(priv->mdio);
+	if (ret) {
+		netdev_err(dev->net, "Could not register MDIO bus (err %d)\n", ret);
+		mdiobus_free(priv->mdio);
+		priv->mdio = NULL;
+	}
+
+	return ret;
+}
+
+static void ax88772_mdio_unregister(struct asix_common_private *priv)
+{
+	mdiobus_unregister(priv->mdio);
+	mdiobus_free(priv->mdio);
 }
 
 static int ax88772_init_phy(struct usbnet *dev)
@@ -681,30 +719,129 @@ static int ax88772_init_phy(struct usbnet *dev)
 	struct asix_common_private *priv = dev->driver_priv;
 	int ret;
 
-	snprintf(priv->phy_name, sizeof(priv->phy_name), PHY_ID_FMT,
-		 priv->mdio->id, priv->phy_addr);
+	priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr);
+	if (!priv->phydev) {
+		netdev_err(dev->net, "Could not find PHY\n");
+		return -ENODEV;
+	}
 
-	priv->phydev = phy_connect(dev->net, priv->phy_name, &asix_adjust_link,
-				   PHY_INTERFACE_MODE_INTERNAL);
-	if (IS_ERR(priv->phydev)) {
-		netdev_err(dev->net, "Could not connect to PHY device %s\n",
-			   priv->phy_name);
-		ret = PTR_ERR(priv->phydev);
+	ret = phylink_connect_phy(priv->phylink, priv->phydev);
+	if (ret) {
+		netdev_err(dev->net, "Could not connect PHY\n");
 		return ret;
 	}
 
 	phy_suspend(priv->phydev);
-	priv->phydev->mac_managed_pm = 1;
+	priv->phydev->mac_managed_pm = true;
 
 	phy_attached_info(priv->phydev);
 
+	if (priv->embd_phy)
+		return 0;
+
+	/* In case main PHY is not the embedded PHY and MAC is RMII clock
+	 * provider, we need to suspend embedded PHY by keeping PLL enabled
+	 * (AX_SWRESET_IPPD == 0).
+	 */
+	priv->phydev_int = mdiobus_get_phy(priv->mdio, AX_EMBD_PHY_ADDR);
+	if (!priv->phydev_int) {
+		rtnl_lock();
+		phylink_disconnect_phy(priv->phylink);
+		rtnl_unlock();
+		netdev_err(dev->net, "Could not find internal PHY\n");
+		return -ENODEV;
+	}
+
+	priv->phydev_int->mac_managed_pm = true;
+	phy_suspend(priv->phydev_int);
+
+	return 0;
+}
+
+static void ax88772_mac_config(struct phylink_config *config, unsigned int mode,
+			      const struct phylink_link_state *state)
+{
+	/* Nothing to do */
+}
+
+static void ax88772_mac_link_down(struct phylink_config *config,
+				 unsigned int mode, phy_interface_t interface)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
+
+	asix_write_medium_mode(dev, 0, 0);
+}
+
+static void ax88772_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 usbnet *dev = netdev_priv(to_net_dev(config->dev));
+	u16 m = AX_MEDIUM_AC | AX_MEDIUM_RE;
+
+	m |= duplex ? AX_MEDIUM_FD : 0;
+
+	switch (speed) {
+	case SPEED_100:
+		m |= AX_MEDIUM_PS;
+		break;
+	case SPEED_10:
+		break;
+	default:
+		return;
+	}
+
+	if (tx_pause)
+		m |= AX_MEDIUM_TFC;
+
+	if (rx_pause)
+		m |= AX_MEDIUM_RFC;
+
+	asix_write_medium_mode(dev, m, 0);
+}
+
+static const struct phylink_mac_ops ax88772_phylink_mac_ops = {
+	.mac_config = ax88772_mac_config,
+	.mac_link_down = ax88772_mac_link_down,
+	.mac_link_up = ax88772_mac_link_up,
+};
+
+static int ax88772_phylink_setup(struct usbnet *dev)
+{
+	struct asix_common_private *priv = dev->driver_priv;
+	phy_interface_t phy_if_mode;
+	struct phylink *phylink;
+
+	priv->phylink_config.dev = &dev->net->dev;
+	priv->phylink_config.type = PHYLINK_NETDEV;
+	priv->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
+		MAC_10 | MAC_100;
+
+	__set_bit(PHY_INTERFACE_MODE_INTERNAL,
+		  priv->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_RMII,
+		  priv->phylink_config.supported_interfaces);
+
+	if (priv->embd_phy)
+		phy_if_mode = PHY_INTERFACE_MODE_INTERNAL;
+	else
+		phy_if_mode = PHY_INTERFACE_MODE_RMII;
+
+	phylink = phylink_create(&priv->phylink_config, dev->net->dev.fwnode,
+				 phy_if_mode, &ax88772_phylink_mac_ops);
+	if (IS_ERR(phylink))
+		return PTR_ERR(phylink);
+
+	priv->phylink = phylink;
 	return 0;
 }
 
 static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 {
-	u8 buf[ETH_ALEN] = {0}, chipcode = 0;
 	struct asix_common_private *priv;
+	u8 buf[ETH_ALEN] = {0};
 	int ret, i;
 
 	priv = devm_kzalloc(&dev->udev->dev, sizeof(*priv), GFP_KERNEL);
@@ -713,7 +850,9 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	dev->driver_priv = priv;
 
-	usbnet_get_endpoints(dev, intf);
+	ret = usbnet_get_endpoints(dev, intf);
+	if (ret)
+		return ret;
 
 	/* Maybe the boot loader passed the MAC address via device tree */
 	if (!eth_platform_get_mac_address(&dev->udev->dev, buf)) {
@@ -753,14 +892,25 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 		return ret;
 
 	priv->phy_addr = ret;
-	priv->embd_phy = ((priv->phy_addr & 0x1f) == 0x10);
+	priv->embd_phy = ((priv->phy_addr & 0x1f) == AX_EMBD_PHY_ADDR);
+
+	ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1,
+			    &priv->chipcode, 0);
+	if (ret < 0) {
+		netdev_dbg(dev->net, "Failed to read STATMNGSTS_REG: %d\n", ret);
+		return ret;
+	}
 
-	asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &chipcode, 0);
-	chipcode &= AX_CHIPCODE_MASK;
+	priv->chipcode &= AX_CHIPCODE_MASK;
 
-	ret = (chipcode == AX_AX88772_CHIPCODE) ? ax88772_hw_reset(dev, 0) :
-						  ax88772a_hw_reset(dev, 0);
+	priv->resume = ax88772_resume;
+	priv->suspend = ax88772_suspend;
+	if (priv->chipcode == AX_AX88772_CHIPCODE)
+		priv->reset = ax88772_hw_reset;
+	else
+		priv->reset = ax88772a_hw_reset;
 
+	ret = priv->reset(dev, 0);
 	if (ret < 0) {
 		netdev_dbg(dev->net, "Failed to reset AX88772: %d\n", ret);
 		return ret;
@@ -775,30 +925,41 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	priv->presvd_phy_bmcr = 0;
 	priv->presvd_phy_advertise = 0;
-	if (chipcode == AX_AX88772_CHIPCODE) {
-		priv->resume = ax88772_resume;
-		priv->suspend = ax88772_suspend;
-	} else {
-		priv->resume = ax88772a_resume;
-		priv->suspend = ax88772_suspend;
-	}
 
 	ret = ax88772_init_mdio(dev);
 	if (ret)
-		return ret;
+		goto mdio_err;
+
+	ret = ax88772_phylink_setup(dev);
+	if (ret)
+		goto phylink_err;
+
+	ret = ax88772_init_phy(dev);
+	if (ret)
+		goto initphy_err;
+
+	/* Keep this interface runtime-PM active by taking a usage ref.
+	 * Prevents runtime suspend while bound and avoids resume paths
+	 * that could deadlock (autoresume under RTNL while USB PM lock
+	 * is held, phylink/MDIO wants RTNL).
+	 */
+	pm_runtime_get_noresume(&intf->dev);
 
-	return ax88772_init_phy(dev);
+	return 0;
+
+initphy_err:
+	phylink_destroy(priv->phylink);
+phylink_err:
+	ax88772_mdio_unregister(priv);
+mdio_err:
+	return ret;
 }
 
 static int ax88772_stop(struct usbnet *dev)
 {
 	struct asix_common_private *priv = dev->driver_priv;
 
-	/* On unplugged USB, we will get MDIO communication errors and the
-	 * PHY will be set in to PHY_HALTED state.
-	 */
-	if (priv->phydev->state != PHY_HALTED)
-		phy_stop(priv->phydev);
+	phylink_stop(priv->phylink);
 
 	return 0;
 }
@@ -807,8 +968,14 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct asix_common_private *priv = dev->driver_priv;
 
-	phy_disconnect(priv->phydev);
+	rtnl_lock();
+	phylink_disconnect_phy(priv->phylink);
+	rtnl_unlock();
+	phylink_destroy(priv->phylink);
+	ax88772_mdio_unregister(priv);
 	asix_rx_fixup_common_free(dev->driver_priv);
+	/* Drop the PM usage ref taken in bind() */
+	pm_runtime_put(&intf->dev);
 }
 
 static void ax88178_unbind(struct usbnet *dev, struct usb_interface *intf)
@@ -858,7 +1025,6 @@ static int marvell_phy_init(struct usbnet *dev)
 		reg = asix_mdio_read(dev->net, dev->mii.phy_id,
 			MII_MARVELL_LED_CTRL);
 		netdev_dbg(dev->net, "MII_MARVELL_LED_CTRL (2) = 0x%04x\n", reg);
-		reg &= 0xfc0f;
 	}
 
 	return 0;
@@ -920,11 +1086,21 @@ static int ax88178_reset(struct usbnet *dev)
 	int gpio0 = 0;
 	u32 phyid;
 
-	asix_read_cmd(dev, AX_CMD_READ_GPIOS, 0, 0, 1, &status, 0);
+	ret = asix_read_cmd(dev, AX_CMD_READ_GPIOS, 0, 0, 1, &status, 0);
+	if (ret < 0) {
+		netdev_dbg(dev->net, "Failed to read GPIOS: %d\n", ret);
+		return ret;
+	}
+
 	netdev_dbg(dev->net, "GPIO Status: 0x%04x\n", status);
 
 	asix_write_cmd(dev, AX_CMD_WRITE_ENABLE, 0, 0, 0, NULL, 0);
-	asix_read_cmd(dev, AX_CMD_READ_EEPROM, 0x0017, 0, 2, &eeprom, 0);
+	ret = asix_read_cmd(dev, AX_CMD_READ_EEPROM, 0x0017, 0, 2, &eeprom, 0);
+	if (ret < 0) {
+		netdev_dbg(dev->net, "Failed to read EEPROM: %d\n", ret);
+		return ret;
+	}
+
 	asix_write_cmd(dev, AX_CMD_WRITE_DISABLE, 0, 0, 0, NULL, 0);
 
 	netdev_dbg(dev->net, "EEPROM index 0x17 is 0x%04x\n", eeprom);
@@ -1081,7 +1257,7 @@ static int ax88178_change_mtu(struct net_device *net, int new_mtu)
 	if ((ll_mtu % dev->maxpacket) == 0)
 		return -EDOM;
 
-	net->mtu = new_mtu;
+	WRITE_ONCE(net->mtu, new_mtu);
 	dev->hard_mtu = net->mtu + net->hard_header_len;
 	ax88178_set_mfb(dev);
 
@@ -1109,7 +1285,9 @@ static int ax88178_bind(struct usbnet *dev, struct usb_interface *intf)
 	int ret;
 	u8 buf[ETH_ALEN] = {0};
 
-	usbnet_get_endpoints(dev,intf);
+	ret = usbnet_get_endpoints(dev, intf);
+	if (ret)
+		return ret;
 
 	/* Get the MAC address */
 	ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf, 0);
@@ -1201,10 +1379,9 @@ static const struct driver_info ax88772_info = {
 	.description = "ASIX AX88772 USB 2.0 Ethernet",
 	.bind = ax88772_bind,
 	.unbind = ax88772_unbind,
-	.status = asix_status,
 	.reset = ax88772_reset,
 	.stop = ax88772_stop,
-	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR | FLAG_MULTI_PACKET,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_MULTI_PACKET,
 	.rx_fixup = asix_rx_fixup_common,
 	.tx_fixup = asix_tx_fixup,
 };
@@ -1213,11 +1390,21 @@ static const struct driver_info ax88772b_info = {
 	.description = "ASIX AX88772B USB 2.0 Ethernet",
 	.bind = ax88772_bind,
 	.unbind = ax88772_unbind,
-	.status = asix_status,
 	.reset = ax88772_reset,
 	.stop = ax88772_stop,
-	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR |
-	         FLAG_MULTI_PACKET,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_MULTI_PACKET,
+	.rx_fixup = asix_rx_fixup_common,
+	.tx_fixup = asix_tx_fixup,
+	.data = FLAG_EEPROM_MAC,
+};
+
+static const struct driver_info lxausb_t1l_info = {
+	.description = "Linux Automation GmbH USB 10Base-T1L",
+	.bind = ax88772_bind,
+	.unbind = ax88772_unbind,
+	.reset = ax88772_reset,
+	.stop = ax88772_stop,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_MULTI_PACKET,
 	.rx_fixup = asix_rx_fixup_common,
 	.tx_fixup = asix_tx_fixup,
 	.data = FLAG_EEPROM_MAC,
@@ -1249,15 +1436,26 @@ static const struct driver_info hg20f9_info = {
 	.description = "HG20F9 USB 2.0 Ethernet",
 	.bind = ax88772_bind,
 	.unbind = ax88772_unbind,
-	.status = asix_status,
 	.reset = ax88772_reset,
-	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR |
-	         FLAG_MULTI_PACKET,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_MULTI_PACKET,
 	.rx_fixup = asix_rx_fixup_common,
 	.tx_fixup = asix_tx_fixup,
 	.data = FLAG_EEPROM_MAC,
 };
 
+static const struct driver_info lyconsys_fibergecko100_info = {
+	.description = "LyconSys FiberGecko 100 USB 2.0 to SFP Adapter",
+	.bind = ax88178_bind,
+	.status = asix_status,
+	.link_reset = ax88178_link_reset,
+	.reset = ax88178_link_reset,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR |
+		 FLAG_MULTI_PACKET,
+	.rx_fixup = asix_rx_fixup_common,
+	.tx_fixup = asix_tx_fixup,
+	.data = 0x20061201,
+};
+
 static const struct usb_device_id	products [] = {
 {
 	// Linksys USB200M
@@ -1411,6 +1609,14 @@ static const struct usb_device_id	products [] = {
 	 */
 	USB_DEVICE(0x066b, 0x20f9),
 	.driver_info = (unsigned long) &hg20f9_info,
+}, {
+	// Linux Automation GmbH USB 10Base-T1L
+	USB_DEVICE(0x33f7, 0x0004),
+	.driver_info = (unsigned long) &lxausb_t1l_info,
+}, {
+	/* LyconSys FiberGecko 100 */
+	USB_DEVICE(0x1d2a, 0x0801),
+	.driver_info = (unsigned long) &lyconsys_fibergecko100_info,
 },
 	{ },		// END
 };
@@ -1424,6 +1630,11 @@ static struct usb_driver asix_driver = {
 	.resume =	asix_resume,
 	.reset_resume =	asix_resume,
 	.disconnect =	usbnet_disconnect,
+	/* usbnet enables autosuspend by default (supports_autosuspend=1).
+	 * We keep runtime-PM active for AX88772* by taking a PM usage
+	 * reference in ax88772_bind() (pm_runtime_get_noresume()) and
+	 * dropping it in unbind(), which effectively blocks autosuspend.
+	 */
 	.supports_autosuspend = 1,
 	.disable_hub_initiated_lpm = 1,
 };