1 files changed, 48 insertions, 14 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 054a76dc5d5..8ea095e5909 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -690,18 +690,11 @@ static void hub_restart(struct usb_hub *hub, enum hub_activation_type type)
                                 set_bit(port1, hub->change_bits);
 
                 } else if (udev->persist_enabled) {
-                        /* Turn off the status changes to prevent khubd
-                         * from disconnecting the device.
-                         */
-                        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);
 #ifdef CONFIG_PM
                         udev->reset_resume = 1;
 #endif
+                        set_bit(port1, hub->change_bits);
+
                 } else {
                         /* The power session is gone; tell khubd */
                         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
@@ -2075,17 +2068,16 @@ 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;
 }
 
@@ -2632,6 +2624,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
         struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
         unsigned wHubCharacteristics =
                         le16_to_cpu(hub->descriptor->wHubCharacteristics);
+        struct usb_device *udev;
         int status, i;
 
         dev_dbg (hub_dev,
@@ -2666,8 +2659,45 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
                 }
         }
 
+        /* 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_composite_device(udev, NULL);
+                }
+                usb_unlock_device(udev);
+
+                if (status == 0) {
+                        clear_bit(port1, hub->change_bits);
+                        return;
+                }
+        }
+
         /* Disconnect any existing devices under this port */
-        if (hdev->children[port1-1])
+        if (udev)
                 usb_disconnect(&hdev->children[port1-1]);
         clear_bit(port1, hub->change_bits);
 
@@ -2685,7 +2715,6 @@ 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
@@ -2944,11 +2973,16 @@ 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 {