1 files changed, 88 insertions, 22 deletions

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 743cbf5d662c..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--) {
@@ -625,6 +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);
@@ -666,8 +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;
 
@@ -675,11 +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)
@@ -738,7 +770,6 @@ static void ax88772_mac_link_down(struct phylink_config *config,
 	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
 
 	asix_write_medium_mode(dev, 0, 0);
-	usbnet_link_change(dev, false, false);
 }
 
 static void ax88772_mac_link_up(struct phylink_config *config,
@@ -769,7 +800,6 @@ static void ax88772_mac_link_up(struct phylink_config *config,
 		m |= AX_MEDIUM_RFC;
 
 	asix_write_medium_mode(dev, m, 0);
-	usbnet_link_change(dev, true, false);
 }
 
 static const struct phylink_mac_ops ax88772_phylink_mac_ops = {
@@ -820,7 +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)) {
@@ -896,16 +928,30 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	ret = ax88772_init_mdio(dev);
 	if (ret)
-		return ret;
+		goto mdio_err;
 
 	ret = ax88772_phylink_setup(dev);
 	if (ret)
-		return ret;
+		goto phylink_err;
 
 	ret = ax88772_init_phy(dev);
 	if (ret)
-		phylink_destroy(priv->phylink);
+		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 0;
 
+initphy_err:
+	phylink_destroy(priv->phylink);
+phylink_err:
+	ax88772_mdio_unregister(priv);
+mdio_err:
 	return ret;
 }
 
@@ -926,7 +972,10 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
 	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)
@@ -1208,7 +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);
 
@@ -1236,7 +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);
@@ -1328,10 +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,
 };
@@ -1340,11 +1390,9 @@ 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,
@@ -1354,11 +1402,9 @@ static const struct driver_info lxausb_t1l_info = {
 	.description = "Linux Automation GmbH USB 10Base-T1L",
 	.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,
@@ -1390,15 +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
@@ -1556,6 +1613,10 @@ static const struct usb_device_id	products [] = {
 	// 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
 };
@@ -1569,6 +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,
 };