1 files changed, 311 insertions, 225 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 4cfe32a16c37..107e1d25ddec 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -72,7 +72,6 @@ struct usb_hub {
 
 	unsigned		limited_power:1;
 	unsigned		quiescing:1;
-	unsigned		activating:1;
 	unsigned		disconnected:1;
 
 	unsigned		has_indicators:1;
@@ -131,6 +130,12 @@ MODULE_PARM_DESC(use_both_schemes,
 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
 
+#define HUB_DEBOUNCE_TIMEOUT	1500
+#define HUB_DEBOUNCE_STEP	  25
+#define HUB_DEBOUNCE_STABLE	 100
+
+
+static int usb_reset_and_verify_device(struct usb_device *udev);
 
 static inline char *portspeed(int portstatus)
 {
@@ -535,37 +540,6 @@ static void hub_power_on(struct usb_hub *hub)
 	msleep(max(pgood_delay, (unsigned) 100));
 }
 
-static void hub_quiesce(struct usb_hub *hub)
-{
-	/* (nonblocking) khubd and related activity won't re-trigger */
-	hub->quiescing = 1;
-	hub->activating = 0;
-
-	/* (blocking) stop khubd and related activity */
-	usb_kill_urb(hub->urb);
-	if (hub->has_indicators)
-		cancel_delayed_work_sync(&hub->leds);
-	if (hub->tt.hub)
-		cancel_work_sync(&hub->tt.kevent);
-}
-
-static void hub_activate(struct usb_hub *hub)
-{
-	int	status;
-
-	hub->quiescing = 0;
-	hub->activating = 1;
-
-	status = usb_submit_urb(hub->urb, GFP_NOIO);
-	if (status < 0)
-		dev_err(hub->intfdev, "activate --> %d\n", status);
-	if (hub->has_indicators && blinkenlights)
-		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
-
-	/* scan all ports ASAP */
-	kick_khubd(hub);
-}
-
 static int hub_hub_status(struct usb_hub *hub,
 		u16 *status, u16 *change)
 {
@@ -624,136 +598,149 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
  	kick_khubd(hub);
 }
 
-/* caller has locked the hub device */
-static void hub_stop(struct usb_hub *hub)
+enum hub_activation_type {
+	HUB_INIT, HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME
+};
+
+static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 {
 	struct usb_device *hdev = hub->hdev;
-	int i;
+	int port1;
+	int status;
+	bool need_debounce_delay = false;
 
-	/* Disconnect all the children */
-	for (i = 0; i < hdev->maxchild; ++i) {
-		if (hdev->children[i])
-			usb_disconnect(&hdev->children[i]);
-	}
-	hub_quiesce(hub);
-}
+	/* After a resume, port power should still be on.
+	 * For any other type of activation, turn it on.
+	 */
+	if (type != HUB_RESUME)
+		hub_power_on(hub);
 
-#define HUB_RESET		1
-#define HUB_RESUME		2
-#define HUB_RESET_RESUME	3
+	/* Check each port and set hub->change_bits to let khubd know
+	 * which ports need attention.
+	 */
+	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
+		struct usb_device *udev = hdev->children[port1-1];
+		u16 portstatus, portchange;
 
-#ifdef CONFIG_PM
+		portstatus = portchange = 0;
+		status = hub_port_status(hub, port1, &portstatus, &portchange);
+		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
+			dev_dbg(hub->intfdev,
+					"port %d: status %04x change %04x\n",
+					port1, portstatus, portchange);
 
-/* Try to identify which devices need USB-PERSIST handling */
-static int persistent_device(struct usb_device *udev)
-{
-	int i;
-	int retval;
-	struct usb_host_config *actconfig;
+		/* After anything other than HUB_RESUME (i.e., initialization
+		 * or any sort of reset), every port should be disabled.
+		 * Unconnected ports should likewise be disabled (paranoia),
+		 * and so should ports for which we have no usb_device.
+		 */
+		if ((portstatus & USB_PORT_STAT_ENABLE) && (
+				type != HUB_RESUME ||
+				!(portstatus & USB_PORT_STAT_CONNECTION) ||
+				!udev ||
+				udev->state == USB_STATE_NOTATTACHED)) {
+			clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
+			portstatus &= ~USB_PORT_STAT_ENABLE;
+		}
 
-	/* Explicitly not marked persistent? */
-	if (!udev->persist_enabled)
-		return 0;
+		/* Clear status-change flags; we'll debounce later */
+		if (portchange & USB_PORT_STAT_C_CONNECTION) {
+			need_debounce_delay = true;
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_CONNECTION);
+		}
+		if (portchange & USB_PORT_STAT_C_ENABLE) {
+			need_debounce_delay = true;
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_ENABLE);
+		}
 
-	/* No active config? */
-	actconfig = udev->actconfig;
-	if (!actconfig)
-		return 0;
+		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
+			/* Tell khubd to disconnect the device or
+			 * check for a new connection
+			 */
+			if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
+				set_bit(port1, hub->change_bits);
+
+		} else if (portstatus & USB_PORT_STAT_ENABLE) {
+			/* The power session apparently survived the resume.
+			 * If there was an overcurrent or suspend change
+			 * (i.e., remote wakeup request), have khubd
+			 * take care of it.
+			 */
+			if (portchange)
+				set_bit(port1, hub->change_bits);
 
-	/* FIXME! We should check whether it's open here or not! */
+		} else if (udev->persist_enabled) {
+#ifdef CONFIG_PM
+			udev->reset_resume = 1;
+#endif
+			set_bit(port1, hub->change_bits);
 
-	/*
-	 * Check that all the interface drivers have a
-	 * 'reset_resume' entrypoint
+		} else {
+			/* The power session is gone; tell khubd */
+			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
+			set_bit(port1, hub->change_bits);
+		}
+	}
+
+	/* If no port-status-change flags were set, we don't need any
+	 * debouncing.  If flags were set we can try to debounce the
+	 * ports all at once right now, instead of letting khubd do them
+	 * one at a time later on.
+	 *
+	 * If any port-status changes do occur during this delay, khubd
+	 * will see them later and handle them normally.
 	 */
-	retval = 0;
-	for (i = 0; i < actconfig->desc.bNumInterfaces; i++) {
-		struct usb_interface *intf;
-		struct usb_driver *driver;
+	if (need_debounce_delay)
+		msleep(HUB_DEBOUNCE_STABLE);
 
-		intf = actconfig->interface[i];
-		if (!intf->dev.driver)
-			continue;
-		driver = to_usb_driver(intf->dev.driver);
-		if (!driver->reset_resume)
-			return 0;
-		/*
-		 * We have at least one driver, and that one
-		 * has a reset_resume method.
-		 */
-		retval = 1;
-	}
-	return retval;
-}
+	hub->quiescing = 0;
 
-static void hub_restart(struct usb_hub *hub, int type)
-{
-	struct usb_device *hdev = hub->hdev;
-	int port1;
+	status = usb_submit_urb(hub->urb, GFP_NOIO);
+	if (status < 0)
+		dev_err(hub->intfdev, "activate --> %d\n", status);
+	if (hub->has_indicators && blinkenlights)
+		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
 
-	/* Check each of the children to see if they require
-	 * USB-PERSIST handling or disconnection.  Also check
-	 * each unoccupied port to make sure it is still disabled.
-	 */
-	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
-		struct usb_device *udev = hdev->children[port1-1];
-		int status = 0;
-		u16 portstatus, portchange;
+	/* Scan all ports that need attention */
+	kick_khubd(hub);
+}
 
-		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
-			if (type != HUB_RESET) {
-				status = hub_port_status(hub, port1,
-						&portstatus, &portchange);
-				if (status == 0 && (portstatus &
-						USB_PORT_STAT_ENABLE))
-					clear_port_feature(hdev, port1,
-							USB_PORT_FEAT_ENABLE);
-			}
-			continue;
-		}
+enum hub_quiescing_type {
+	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
+};
 
-		/* Was the power session lost while we were suspended? */
-		status = hub_port_status(hub, port1, &portstatus, &portchange);
+static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
+{
+	struct usb_device *hdev = hub->hdev;
+	int i;
 
-		/* If the device is gone, khubd will handle it later */
-		if (status == 0 && !(portstatus & USB_PORT_STAT_CONNECTION))
-			continue;
+	/* khubd and related activity won't re-trigger */
+	hub->quiescing = 1;
 
-		/* For "USB_PERSIST"-enabled children we must
-		 * mark the child device for reset-resume and
-		 * turn off the various status changes to prevent
-		 * khubd from disconnecting it later.
-		 */
-		if (status == 0 && !(portstatus & USB_PORT_STAT_ENABLE) &&
-				persistent_device(udev)) {
-			if (portchange & USB_PORT_STAT_C_ENABLE)
-				clear_port_feature(hub->hdev, port1,
-						USB_PORT_FEAT_C_ENABLE);
-			if (portchange & USB_PORT_STAT_C_CONNECTION)
-				clear_port_feature(hub->hdev, port1,
-						USB_PORT_FEAT_C_CONNECTION);
-			udev->reset_resume = 1;
+	if (type != HUB_SUSPEND) {
+		/* Disconnect all the children */
+		for (i = 0; i < hdev->maxchild; ++i) {
+			if (hdev->children[i])
+				usb_disconnect(&hdev->children[i]);
 		}
-
-		/* Otherwise for a reset_resume we must disconnect the child,
-		 * but as we may not lock the child device here
-		 * we have to do a "logical" disconnect.
-		 */
-		else if (type == HUB_RESET_RESUME)
-			hub_port_logical_disconnect(hub, port1);
 	}
 
-	hub_activate(hub);
+	/* Stop khubd and related activity */
+	usb_kill_urb(hub->urb);
+	if (hub->has_indicators)
+		cancel_delayed_work_sync(&hub->leds);
+	if (hub->tt.hub)
+		cancel_work_sync(&hub->tt.kevent);
 }
 
-#endif	/* CONFIG_PM */
-
 /* caller has locked the hub device */
 static int hub_pre_reset(struct usb_interface *intf)
 {
 	struct usb_hub *hub = usb_get_intfdata(intf);
 
-	hub_stop(hub);
+	hub_quiesce(hub, HUB_PRE_RESET);
 	return 0;
 }
 
@@ -762,8 +749,7 @@ static int hub_post_reset(struct usb_interface *intf)
 {
 	struct usb_hub *hub = usb_get_intfdata(intf);
 
-	hub_power_on(hub);
-	hub_activate(hub);
+	hub_activate(hub, HUB_POST_RESET);
 	return 0;
 }
 
@@ -1009,8 +995,7 @@ static int hub_configure(struct usb_hub *hub,
 	if (hub->has_indicators && blinkenlights)
 		hub->indicator [0] = INDICATOR_CYCLE;
 
-	hub_power_on(hub);
-	hub_activate(hub);
+	hub_activate(hub, HUB_INIT);
 	return 0;
 
 fail:
@@ -1042,7 +1027,7 @@ static void hub_disconnect(struct usb_interface *intf)
 
 	/* Disconnect all children and quiesce the hub */
 	hub->error = 0;
-	hub_stop(hub);
+	hub_quiesce(hub, HUB_DISCONNECT);
 
 	usb_set_intfdata (intf, NULL);
 
@@ -1068,6 +1053,12 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	desc = intf->cur_altsetting;
 	hdev = interface_to_usbdev(intf);
 
+	if (hdev->level == MAX_TOPO_LEVEL) {
+		dev_err(&intf->dev, "Unsupported bus topology: "
+				"hub nested too deep\n");
+		return -E2BIG;
+	}
+
 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
 	if (hdev->parent) {
 		dev_warn(&intf->dev, "ignoring external hub\n");
@@ -1814,6 +1805,51 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 
 #ifdef	CONFIG_PM
 
+#define MASK_BITS	(USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
+				USB_PORT_STAT_SUSPEND)
+#define WANT_BITS	(USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
+
+/* Determine whether the device on a port is ready for a normal resume,
+ * is ready for a reset-resume, or should be disconnected.
+ */
+static int check_port_resume_type(struct usb_device *udev,
+		struct usb_hub *hub, int port1,
+		int status, unsigned portchange, unsigned portstatus)
+{
+	/* Is the device still present? */
+	if (status || (portstatus & MASK_BITS) != WANT_BITS) {
+		if (status >= 0)
+			status = -ENODEV;
+	}
+
+	/* Can't do a normal resume if the port isn't enabled,
+	 * so try a reset-resume instead.
+	 */
+	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
+		if (udev->persist_enabled)
+			udev->reset_resume = 1;
+		else
+			status = -ENODEV;
+	}
+
+	if (status) {
+		dev_dbg(hub->intfdev,
+				"port %d status %04x.%04x after resume, %d\n",
+				port1, portchange, portstatus, status);
+	} else if (udev->reset_resume) {
+
+		/* Late port handoff can set status-change bits */
+		if (portchange & USB_PORT_STAT_C_CONNECTION)
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_CONNECTION);
+		if (portchange & USB_PORT_STAT_C_ENABLE)
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_ENABLE);
+	}
+
+	return status;
+}
+
 #ifdef	CONFIG_USB_SUSPEND
 
 /*
@@ -1943,7 +1979,8 @@ static int finish_port_resume(struct usb_device *udev)
 	 * resumed.
 	 */
 	if (udev->reset_resume)
-		status = usb_reset_device(udev);
+ retry_reset_resume:
+		status = usb_reset_and_verify_device(udev);
 
  	/* 10.5.4.5 says be sure devices in the tree are still there.
  	 * For now let's assume the device didn't go crazy on resume,
@@ -1954,6 +1991,13 @@ static int finish_port_resume(struct usb_device *udev)
 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
 		if (status >= 0)
 			status = (status > 0 ? 0 : -ENODEV);
+
+		/* If a normal resume failed, try doing a reset-resume */
+		if (status && !udev->reset_resume && udev->persist_enabled) {
+			dev_dbg(&udev->dev, "retry with reset-resume\n");
+			udev->reset_resume = 1;
+			goto retry_reset_resume;
+		}
 	}
 
 	if (status) {
@@ -2002,7 +2046,7 @@ static int finish_port_resume(struct usb_device *udev)
  * to it will be lost.  Using the USB_PERSIST facility, the device can be
  * made to appear as if it had not disconnected.
  *
- * This facility can be dangerous.  Although usb_reset_device() makes
+ * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
  * every effort to insure that the same device is present after the
  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
  * quite possible for a device to remain unaltered but its media to be
@@ -2018,7 +2062,6 @@ int usb_port_resume(struct usb_device *udev)
 	int		port1 = udev->portnum;
 	int		status;
 	u16		portchange, portstatus;
-	unsigned	mask_flags, want_flags;
 
 	/* Skip the initial Clear-Suspend step for a remote wakeup */
 	status = hub_port_status(hub, port1, &portstatus, &portchange);
@@ -2047,35 +2090,23 @@ int usb_port_resume(struct usb_device *udev)
 		 */
 		status = hub_port_status(hub, port1, &portstatus, &portchange);
 
- SuspendCleared:
-		if (udev->reset_resume)
-			want_flags = USB_PORT_STAT_POWER
-					| USB_PORT_STAT_CONNECTION;
-		else
-			want_flags = USB_PORT_STAT_POWER
-					| USB_PORT_STAT_CONNECTION
-					| USB_PORT_STAT_ENABLE;
-		mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
+		/* TRSMRCY = 10 msec */
+		msleep(10);
+	}
 
-		if (status < 0 || (portstatus & mask_flags) != want_flags) {
-			dev_dbg(hub->intfdev,
-				"port %d status %04x.%04x after resume, %d\n",
-				port1, portchange, portstatus, status);
-			if (status >= 0)
-				status = -ENODEV;
-		} else {
-			if (portchange & USB_PORT_STAT_C_SUSPEND)
-				clear_port_feature(hub->hdev, port1,
-						USB_PORT_FEAT_C_SUSPEND);
-			/* TRSMRCY = 10 msec */
-			msleep(10);
-		}
+ SuspendCleared:
+	if (status == 0) {
+		if (portchange & USB_PORT_STAT_C_SUSPEND)
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_SUSPEND);
 	}
 
 	clear_bit(port1, hub->busy_bits);
 	if (!hub->hdev->parent && !hub->busy_bits[0])
 		usb_enable_root_hub_irq(hub->hdev->bus);
 
+	status = check_port_resume_type(udev,
+			hub, port1, status, portchange, portstatus);
 	if (status == 0)
 		status = finish_port_resume(udev);
 	if (status < 0) {
@@ -2085,17 +2116,16 @@ int usb_port_resume(struct usb_device *udev)
 	return status;
 }
 
+/* caller has locked udev */
 static int remote_wakeup(struct usb_device *udev)
 {
 	int	status = 0;
 
-	usb_lock_device(udev);
 	if (udev->state == USB_STATE_SUSPENDED) {
 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
 		usb_mark_last_busy(udev);
 		status = usb_external_resume_device(udev);
 	}
-	usb_unlock_device(udev);
 	return status;
 }
 
@@ -2108,14 +2138,25 @@ int usb_port_suspend(struct usb_device *udev)
 	return 0;
 }
 
+/* However we may need to do a reset-resume */
+
 int usb_port_resume(struct usb_device *udev)
 {
-	int status = 0;
+	struct usb_hub	*hub = hdev_to_hub(udev->parent);
+	int		port1 = udev->portnum;
+	int		status;
+	u16		portchange, portstatus;
 
-	/* However we may need to do a reset-resume */
-	if (udev->reset_resume) {
+	status = hub_port_status(hub, port1, &portstatus, &portchange);
+	status = check_port_resume_type(udev,
+			hub, port1, status, portchange, portstatus);
+
+	if (status) {
+		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
+		hub_port_logical_disconnect(hub, port1);
+	} else if (udev->reset_resume) {
 		dev_dbg(&udev->dev, "reset-resume\n");
-		status = usb_reset_device(udev);
+		status = usb_reset_and_verify_device(udev);
 	}
 	return status;
 }
@@ -2149,7 +2190,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 	dev_dbg(&intf->dev, "%s\n", __func__);
 
 	/* stop khubd and related activity */
-	hub_quiesce(hub);
+	hub_quiesce(hub, HUB_SUSPEND);
 	return 0;
 }
 
@@ -2158,7 +2199,7 @@ static int hub_resume(struct usb_interface *intf)
 	struct usb_hub *hub = usb_get_intfdata(intf);
 
 	dev_dbg(&intf->dev, "%s\n", __func__);
-	hub_restart(hub, HUB_RESUME);
+	hub_activate(hub, HUB_RESUME);
 	return 0;
 }
 
@@ -2167,8 +2208,7 @@ static int hub_reset_resume(struct usb_interface *intf)
 	struct usb_hub *hub = usb_get_intfdata(intf);
 
 	dev_dbg(&intf->dev, "%s\n", __func__);
-	hub_power_on(hub);
-	hub_restart(hub, HUB_RESET_RESUME);
+	hub_activate(hub, HUB_RESET_RESUME);
 	return 0;
 }
 
@@ -2218,11 +2258,6 @@ static inline int remote_wakeup(struct usb_device *udev)
  * every 25ms for transient disconnects.  When the port status has been
  * unchanged for 100ms it returns the port status.
  */
-
-#define HUB_DEBOUNCE_TIMEOUT	1500
-#define HUB_DEBOUNCE_STEP	  25
-#define HUB_DEBOUNCE_STABLE	 100
-
 static int hub_port_debounce(struct usb_hub *hub, int port1)
 {
 	int ret;
@@ -2302,7 +2337,7 @@ static int hub_set_address(struct usb_device *udev, int devnum)
  * Returns device in USB_STATE_ADDRESS, except on error.
  *
  * If this is called for an already-existing device (as part of
- * usb_reset_device), the caller must own the device lock.  For a
+ * usb_reset_and_verify_device), the caller must own the device lock.  For a
  * newly detected device that is not accessible through any global
  * pointers, it's not necessary to lock the device.
  */
@@ -2619,7 +2654,7 @@ hub_power_remaining (struct usb_hub *hub)
  * This routine is called when:
  * 	a port connection-change occurs;
  *	a port enable-change occurs (often caused by EMI);
- *	usb_reset_device() encounters changed descriptors (as from
+ *	usb_reset_and_verify_device() encounters changed descriptors (as from
  *		a firmware download)
  * caller already locked the hub
  */
@@ -2629,9 +2664,11 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 	struct usb_device *hdev = hub->hdev;
 	struct device *hub_dev = hub->intfdev;
 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
-	u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
+	unsigned wHubCharacteristics =
+			le16_to_cpu(hub->descriptor->wHubCharacteristics);
+	struct usb_device *udev;
 	int status, i;
- 
+
 	dev_dbg (hub_dev,
 		"port %d, status %04x, change %04x, %s\n",
 		port1, portstatus, portchange, portspeed (portstatus));
@@ -2640,30 +2677,73 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 		set_port_led(hub, port1, HUB_LED_AUTO);
 		hub->indicator[port1-1] = INDICATOR_AUTO;
 	}
- 
-	/* Disconnect any existing devices under this port */
-	if (hdev->children[port1-1])
-		usb_disconnect(&hdev->children[port1-1]);
-	clear_bit(port1, hub->change_bits);
 
 #ifdef	CONFIG_USB_OTG
 	/* during HNP, don't repeat the debounce */
 	if (hdev->bus->is_b_host)
-		portchange &= ~USB_PORT_STAT_C_CONNECTION;
+		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
+				USB_PORT_STAT_C_ENABLE);
 #endif
 
-	if (portchange & USB_PORT_STAT_C_CONNECTION) {
+	/* Try to use the debounce delay for protection against
+	 * port-enable changes caused, for example, by EMI.
+	 */
+	if (portchange & (USB_PORT_STAT_C_CONNECTION |
+				USB_PORT_STAT_C_ENABLE)) {
 		status = hub_port_debounce(hub, port1);
 		if (status < 0) {
 			if (printk_ratelimit())
 				dev_err (hub_dev, "connect-debounce failed, "
 						"port %d disabled\n", port1);
-			goto done;
+			portstatus &= ~USB_PORT_STAT_CONNECTION;
+		} else {
+			portstatus = status;
+		}
+	}
+
+	/* Try to resuscitate an existing device */
+	udev = hdev->children[port1-1];
+	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
+			udev->state != USB_STATE_NOTATTACHED) {
+
+		usb_lock_device(udev);
+		if (portstatus & USB_PORT_STAT_ENABLE) {
+			status = 0;		/* Nothing to do */
+		} else if (!udev->persist_enabled) {
+			status = -ENODEV;	/* Mustn't resuscitate */
+
+#ifdef CONFIG_USB_SUSPEND
+		} else if (udev->state == USB_STATE_SUSPENDED) {
+			/* For a suspended device, treat this as a
+			 * remote wakeup event.
+			 */
+			if (udev->do_remote_wakeup)
+				status = remote_wakeup(udev);
+
+			/* Otherwise leave it be; devices can't tell the
+			 * difference between suspended and disabled.
+			 */
+			else
+				status = 0;
+#endif
+
+		} else {
+			status = usb_reset_device(udev);
+		}
+		usb_unlock_device(udev);
+
+		if (status == 0) {
+			clear_bit(port1, hub->change_bits);
+			return;
 		}
-		portstatus = status;
 	}
 
-	/* Return now if nothing is connected */
+	/* Disconnect any existing devices under this port */
+	if (udev)
+		usb_disconnect(&hdev->children[port1-1]);
+	clear_bit(port1, hub->change_bits);
+
+	/* Return now if debouncing failed or nothing is connected */
 	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
 
 		/* maybe switch power back on (e.g. root hub was reset) */
@@ -2677,7 +2757,6 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 	}
 
 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
-		struct usb_device *udev;
 
 		/* reallocate for each attempt, since references
 		 * to the previous one can escape in various ways
@@ -2858,7 +2937,7 @@ static void hub_events(void)
 		/* If the hub has died, clean up after it */
 		if (hdev->state == USB_STATE_NOTATTACHED) {
 			hub->error = -ENODEV;
-			hub_stop(hub);
+			hub_quiesce(hub, HUB_DISCONNECT);
 			goto loop;
 		}
 
@@ -2877,7 +2956,7 @@ static void hub_events(void)
 			dev_dbg (hub_dev, "resetting for error %d\n",
 				hub->error);
 
-			ret = usb_reset_composite_device(hdev, intf);
+			ret = usb_reset_device(hdev);
 			if (ret) {
 				dev_dbg (hub_dev,
 					"error resetting hub: %d\n", ret);
@@ -2894,7 +2973,7 @@ static void hub_events(void)
 				continue;
 			connect_change = test_bit(i, hub->change_bits);
 			if (!test_and_clear_bit(i, hub->event_bits) &&
-					!connect_change && !hub->activating)
+					!connect_change)
 				continue;
 
 			ret = hub_port_status(hub, i,
@@ -2902,11 +2981,6 @@ static void hub_events(void)
 			if (ret < 0)
 				continue;
 
-			if (hub->activating && !hdev->children[i-1] &&
-					(portstatus &
-						USB_PORT_STAT_CONNECTION))
-				connect_change = 1;
-
 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
 				clear_port_feature(hdev, i,
 					USB_PORT_FEAT_C_CONNECTION);
@@ -2941,11 +3015,16 @@ static void hub_events(void)
 			}
 
 			if (portchange & USB_PORT_STAT_C_SUSPEND) {
+				struct usb_device *udev;
+
 				clear_port_feature(hdev, i,
 					USB_PORT_FEAT_C_SUSPEND);
-				if (hdev->children[i-1]) {
+				udev = hdev->children[i-1];
+				if (udev) {
+					usb_lock_device(udev);
 					ret = remote_wakeup(hdev->
 							children[i-1]);
+					usb_unlock_device(udev);
 					if (ret < 0)
 						connect_change = 1;
 				} else {
@@ -3002,8 +3081,6 @@ static void hub_events(void)
 			}
 		}
 
-		hub->activating = 0;
-
 		/* If this is a root hub, tell the HCD it's okay to
 		 * re-enable port-change interrupts now. */
 		if (!hdev->parent && !hub->busy_bits[0])
@@ -3172,12 +3249,12 @@ static int descriptors_changed(struct usb_device *udev,
 }
 
 /**
- * usb_reset_device - perform a USB port reset to reinitialize a device
+ * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
  *
  * WARNING - don't use this routine to reset a composite device
  * (one with multiple interfaces owned by separate drivers)!
- * Use usb_reset_composite_device() instead.
+ * Use usb_reset_device() instead.
  *
  * Do a port reset, reassign the device's address, and establish its
  * former operating configuration.  If the reset fails, or the device's
@@ -3201,7 +3278,7 @@ static int descriptors_changed(struct usb_device *udev,
  * holding the device lock because these tasks should always call
  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
  */
-int usb_reset_device(struct usb_device *udev)
+static int usb_reset_and_verify_device(struct usb_device *udev)
 {
 	struct usb_device		*parent_hdev = udev->parent;
 	struct usb_hub			*parent_hub;
@@ -3289,26 +3366,28 @@ re_enumerate:
 	hub_port_logical_disconnect(parent_hub, port1);
 	return -ENODEV;
 }
-EXPORT_SYMBOL_GPL(usb_reset_device);
 
 /**
- * usb_reset_composite_device - warn interface drivers and perform a USB port reset
+ * usb_reset_device - warn interface drivers and perform a USB port reset
  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
- * @iface: interface bound to the driver making the request (optional)
  *
  * Warns all drivers bound to registered interfaces (using their pre_reset
  * method), performs the port reset, and then lets the drivers know that
  * the reset is over (using their post_reset method).
  *
- * Return value is the same as for usb_reset_device().
+ * Return value is the same as for usb_reset_and_verify_device().
  *
  * The caller must own the device lock.  For example, it's safe to use
  * this from a driver probe() routine after downloading new firmware.
  * For calls that might not occur during probe(), drivers should lock
  * the device using usb_lock_device_for_reset().
+ *
+ * If an interface is currently being probed or disconnected, we assume
+ * its driver knows how to handle resets.  For all other interfaces,
+ * if the driver doesn't have pre_reset and post_reset methods then
+ * we attempt to unbind it and rebind afterward.
  */
-int usb_reset_composite_device(struct usb_device *udev,
-		struct usb_interface *iface)
+int usb_reset_device(struct usb_device *udev)
 {
 	int ret;
 	int i;
@@ -3324,40 +3403,47 @@ int usb_reset_composite_device(struct usb_device *udev,
 	/* Prevent autosuspend during the reset */
 	usb_autoresume_device(udev);
 
-	if (iface && iface->condition != USB_INTERFACE_BINDING)
-		iface = NULL;
-
 	if (config) {
 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 			struct usb_interface *cintf = config->interface[i];
 			struct usb_driver *drv;
+			int unbind = 0;
 
 			if (cintf->dev.driver) {
 				drv = to_usb_driver(cintf->dev.driver);
-				if (drv->pre_reset)
-					(drv->pre_reset)(cintf);
-	/* FIXME: Unbind if pre_reset returns an error or isn't defined */
+				if (drv->pre_reset && drv->post_reset)
+					unbind = (drv->pre_reset)(cintf);
+				else if (cintf->condition ==
+						USB_INTERFACE_BOUND)
+					unbind = 1;
+				if (unbind)
+					usb_forced_unbind_intf(cintf);
 			}
 		}
 	}
 
-	ret = usb_reset_device(udev);
+	ret = usb_reset_and_verify_device(udev);
 
 	if (config) {
 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
 			struct usb_interface *cintf = config->interface[i];
 			struct usb_driver *drv;
+			int rebind = cintf->needs_binding;
 
-			if (cintf->dev.driver) {
+			if (!rebind && cintf->dev.driver) {
 				drv = to_usb_driver(cintf->dev.driver);
 				if (drv->post_reset)
-					(drv->post_reset)(cintf);
-	/* FIXME: Unbind if post_reset returns an error or isn't defined */
+					rebind = (drv->post_reset)(cintf);
+				else if (cintf->condition ==
+						USB_INTERFACE_BOUND)
+					rebind = 1;
 			}
+			if (rebind)
+				usb_rebind_intf(cintf);
 		}
 	}
 
 	usb_autosuspend_device(udev);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(usb_reset_composite_device);
+EXPORT_SYMBOL_GPL(usb_reset_device);