4 files changed, 55 insertions, 13 deletions

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 792ddda1ad49..85bd5d845409 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -625,6 +625,21 @@ 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);
@@ -919,6 +934,13 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 	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 0;
 
 initphy_err:
@@ -948,6 +970,8 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
 	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)
@@ -1600,6 +1624,11 @@ 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,
 };
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index b56e2459ee3c..00397a807393 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1080,10 +1080,13 @@ static int lan78xx_read_raw_eeprom(struct lan78xx_net *dev, u32 offset,
 	}
 
 read_raw_eeprom_done:
-	if (dev->chipid == ID_REV_CHIP_ID_7800_)
-		return lan78xx_write_reg(dev, HW_CFG, saved);
-
-	return 0;
+	if (dev->chipid == ID_REV_CHIP_ID_7800_) {
+		int rc = lan78xx_write_reg(dev, HW_CFG, saved);
+		/* If USB fails, there is nothing to do */
+		if (rc < 0)
+			return rc;
+	}
+	return ret;
 }
 
 static int lan78xx_read_eeprom(struct lan78xx_net *dev, u32 offset,
@@ -1172,10 +1175,13 @@ static int lan78xx_write_raw_eeprom(struct lan78xx_net *dev, u32 offset,
 	}
 
 write_raw_eeprom_done:
-	if (dev->chipid == ID_REV_CHIP_ID_7800_)
-		return lan78xx_write_reg(dev, HW_CFG, saved);
-
-	return 0;
+	if (dev->chipid == ID_REV_CHIP_ID_7800_) {
+		int rc = lan78xx_write_reg(dev, HW_CFG, saved);
+		/* If USB fails, there is nothing to do */
+		if (rc < 0)
+			return rc;
+	}
+	return ret;
 }
 
 static int lan78xx_read_raw_otp(struct lan78xx_net *dev, u32 offset,
@@ -3244,10 +3250,6 @@ static int lan78xx_reset(struct lan78xx_net *dev)
 		}
 	} while (buf & HW_CFG_LRST_);
 
-	ret = lan78xx_init_mac_address(dev);
-	if (ret < 0)
-		return ret;
-
 	/* save DEVID for later usage */
 	ret = lan78xx_read_reg(dev, ID_REV, &buf);
 	if (ret < 0)
@@ -3256,6 +3258,10 @@ static int lan78xx_reset(struct lan78xx_net *dev)
 	dev->chipid = (buf & ID_REV_CHIP_ID_MASK_) >> 16;
 	dev->chiprev = buf & ID_REV_CHIP_REV_MASK_;
 
+	ret = lan78xx_init_mac_address(dev);
+	if (ret < 0)
+		return ret;
+
 	/* Respond to the IN token with a NAK */
 	ret = lan78xx_read_reg(dev, USB_CFG0, &buf);
 	if (ret < 0)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 44cba7acfe7d..a22d4bb2cf3b 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -10122,7 +10122,12 @@ static int __init rtl8152_driver_init(void)
 	ret = usb_register_device_driver(&rtl8152_cfgselector_driver, THIS_MODULE);
 	if (ret)
 		return ret;
-	return usb_register(&rtl8152_driver);
+
+	ret = usb_register(&rtl8152_driver);
+	if (ret)
+		usb_deregister_device_driver(&rtl8152_cfgselector_driver);
+
+	return ret;
 }
 
 static void __exit rtl8152_driver_exit(void)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 511c4154cf74..bf01f2728531 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -702,6 +702,7 @@ void usbnet_resume_rx(struct usbnet *dev)
 	struct sk_buff *skb;
 	int num = 0;
 
+	local_bh_disable();
 	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 
 	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
@@ -710,6 +711,7 @@ void usbnet_resume_rx(struct usbnet *dev)
 	}
 
 	queue_work(system_bh_wq, &dev->bh_work);
+	local_bh_enable();
 
 	netif_dbg(dev, rx_status, dev->net,
 		  "paused rx queue disabled, %d skbs requeued\n", num);