1 files changed, 36 insertions, 46 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index eaffb0248de1..d7c3d5a35946 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2896,10 +2896,12 @@ static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
  */
 static int check_port_resume_type(struct usb_device *udev,
 		struct usb_hub *hub, int port1,
-		int status, unsigned portchange, unsigned portstatus)
+		int status, u16 portchange, u16 portstatus)
 {
 	struct usb_port *port_dev = hub->ports[port1 - 1];
+	int retries = 3;
 
+ retry:
 	/* Is a warm reset needed to recover the connection? */
 	if (status == 0 && udev->reset_resume
 		&& hub_port_warm_reset_required(hub, port1, portstatus)) {
@@ -2907,10 +2909,17 @@ static int check_port_resume_type(struct usb_device *udev,
 	}
 	/* Is the device still present? */
 	else if (status || port_is_suspended(hub, portstatus) ||
-			!port_is_power_on(hub, portstatus) ||
-			!(portstatus & USB_PORT_STAT_CONNECTION)) {
+			!port_is_power_on(hub, portstatus)) {
 		if (status >= 0)
 			status = -ENODEV;
+	} else if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
+		if (retries--) {
+			usleep_range(200, 300);
+			status = hub_port_status(hub, port1, &portstatus,
+							     &portchange);
+			goto retry;
+		}
+		status = -ENODEV;
 	}
 
 	/* Can't do a normal resume if the port isn't enabled,
@@ -4643,9 +4652,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
 			test_bit(port1, hub->removed_bits)) {
 
-		/* maybe switch power back on (e.g. root hub was reset) */
+		/*
+		 * maybe switch power back on (e.g. root hub was reset)
+		 * but only if the port isn't owned by someone else.
+		 */
 		if (hub_is_port_power_switchable(hub)
-				&& !port_is_power_on(hub, portstatus))
+				&& !port_is_power_on(hub, portstatus)
+				&& !port_dev->port_owner)
 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 
 		if (portstatus & USB_PORT_STAT_ENABLE)
@@ -4870,7 +4883,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 static void port_event(struct usb_hub *hub, int port1)
 		__must_hold(&port_dev->status_lock)
 {
-	int connect_change, reset_device = 0;
+	int connect_change;
 	struct usb_port *port_dev = hub->ports[port1 - 1];
 	struct usb_device *udev = port_dev->child;
 	struct usb_device *hdev = hub->hdev;
@@ -4958,30 +4971,14 @@ static void port_event(struct usb_hub *hub, int port1)
 			if (hub_port_reset(hub, port1, NULL,
 					HUB_BH_RESET_TIME, true) < 0)
 				hub_port_disable(hub, port1, 1);
-		} else
-			reset_device = 1;
-	}
-
-	/*
-	 * On disconnect USB3 protocol ports transit from U0 to
-	 * SS.Inactive to Rx.Detect. If this happens a warm-
-	 * reset is not needed, but a (re)connect may happen
-	 * before hub_wq runs and sees the disconnect, and the
-	 * device may be an unknown state.
-	 *
-	 * If the port went through SS.Inactive without hub_wq
-	 * seeing it the C_LINK_STATE change flag will be set,
-	 * and we reset the dev to put it in a known state.
-	 */
-	if (reset_device || (udev && hub_is_superspeed(hub->hdev)
-				&& (portchange & USB_PORT_STAT_C_LINK_STATE)
-				&& (portstatus & USB_PORT_STAT_CONNECTION))) {
-		usb_unlock_port(port_dev);
-		usb_lock_device(udev);
-		usb_reset_device(udev);
-		usb_unlock_device(udev);
-		usb_lock_port(port_dev);
-		connect_change = 0;
+		} else {
+			usb_unlock_port(port_dev);
+			usb_lock_device(udev);
+			usb_reset_device(udev);
+			usb_unlock_device(udev);
+			usb_lock_port(port_dev);
+			connect_change = 0;
+		}
 	}
 
 	if (connect_change)
@@ -5577,26 +5574,19 @@ EXPORT_SYMBOL_GPL(usb_reset_device);
  *   possible; depending on how the driver attached to each interface
  *   handles ->pre_reset(), the second reset might happen or not.
  *
- * - If a driver is unbound and it had a pending reset, the reset will
- *   be cancelled.
- *
- * - This function can be called during .probe() or .disconnect()
- *   times. On return from .disconnect(), any pending resets will be
- *   cancelled.
- *
- * There is no no need to lock/unlock the @reset_ws as schedule_work()
- * does its own.
+ * - If the reset is delayed so long that the interface is unbound from
+ *   its driver, the reset will be skipped.
  *
- * NOTE: We don't do any reference count tracking because it is not
- *     needed. The lifecycle of the work_struct is tied to the
- *     usb_interface. Before destroying the interface we cancel the
- *     work_struct, so the fact that work_struct is queued and or
- *     running means the interface (and thus, the device) exist and
- *     are referenced.
+ * - This function can be called during .probe().  It can also be called
+ *   during .disconnect(), but doing so is pointless because the reset
+ *   will not occur.  If you really want to reset the device during
+ *   .disconnect(), call usb_reset_device() directly -- but watch out
+ *   for nested unbinding issues!
  */
 void usb_queue_reset_device(struct usb_interface *iface)
 {
-	schedule_work(&iface->reset_ws);
+	if (schedule_work(&iface->reset_ws))
+		usb_get_intf(iface);
 }
 EXPORT_SYMBOL_GPL(usb_queue_reset_device);