2 files changed, 37 insertions, 14 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 28f5bbae35e0..6346fb2acbd7 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2039,6 +2039,18 @@ static void hub_free_dev(struct usb_device *udev)
                 hcd->driver->free_dev(hcd, udev);
 }
 
+static void hub_disconnect_children(struct usb_device *udev)
+{
+        struct usb_hub *hub = usb_hub_to_struct_hub(udev);
+        int i;
+
+        /* Free up all the children before we remove this device */
+        for (i = 0; i < udev->maxchild; i++) {
+                if (hub->ports[i]->child)
+                        usb_disconnect(&hub->ports[i]->child);
+        }
+}
+
 /**
  * usb_disconnect - disconnect a device (usbcore-internal)
  * @pdev: pointer to device being disconnected
@@ -2057,9 +2069,10 @@ static void hub_free_dev(struct usb_device *udev)
  */
 void usb_disconnect(struct usb_device **pdev)
 {
-        struct usb_device       *udev = *pdev;
-        struct usb_hub          *hub = usb_hub_to_struct_hub(udev);
-        int                     i;
+        struct usb_port *port_dev = NULL;
+        struct usb_device *udev = *pdev;
+        struct usb_hub *hub;
+        int port1;
 
         /* mark the device as inactive, so any further urb submissions for
          * this device (and any of its children) will fail immediately.
@@ -2071,11 +2084,7 @@ void usb_disconnect(struct usb_device **pdev)
 
         usb_lock_device(udev);
 
-        /* Free up all the children before we remove this device */
-        for (i = 0; i < udev->maxchild; i++) {
-                if (hub->ports[i]->child)
-                        usb_disconnect(&hub->ports[i]->child);
-        }
+        hub_disconnect_children(udev);
 
         /* deallocate hcd/hardware state ... nuking all pending urbs and
          * cleaning up all state associated with the current configuration
@@ -2086,15 +2095,19 @@ void usb_disconnect(struct usb_device **pdev)
         usb_hcd_synchronize_unlinks(udev);
 
         if (udev->parent) {
-                int port1 = udev->portnum;
-                struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
-                struct usb_port *port_dev = hub->ports[port1 - 1];
+                port1 = udev->portnum;
+                hub = usb_hub_to_struct_hub(udev->parent);
+                port_dev = hub->ports[port1 - 1];
 
                 sysfs_remove_link(&udev->dev.kobj, "port");
                 sysfs_remove_link(&port_dev->dev.kobj, "device");
 
-                if (test_and_clear_bit(port1, hub->child_usage_bits))
-                        pm_runtime_put(&port_dev->dev);
+                /*
+                 * As usb_port_runtime_resume() de-references udev, make
+                 * sure no resumes occur during removal
+                 */
+                if (!test_and_set_bit(port1, hub->child_usage_bits))
+                        pm_runtime_get_sync(&port_dev->dev);
         }
 
         usb_remove_ep_devs(&udev->ep0);
@@ -2116,6 +2129,9 @@ void usb_disconnect(struct usb_device **pdev)
         *pdev = NULL;
         spin_unlock_irq(&device_state_lock);
 
+        if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
+                pm_runtime_put(&port_dev->dev);
+
         hub_free_dev(udev);
 
         put_device(&udev->dev);
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 8b1655700104..62036faf56c0 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -76,6 +76,7 @@ static int usb_port_runtime_resume(struct device *dev)
         struct usb_device *hdev = to_usb_device(dev->parent->parent);
         struct usb_interface *intf = to_usb_interface(dev->parent);
         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+        struct usb_device *udev = port_dev->child;
         struct usb_port *peer = port_dev->peer;
         int port1 = port_dev->portnum;
         int retval;
@@ -97,7 +98,7 @@ static int usb_port_runtime_resume(struct device *dev)
         usb_autopm_get_interface(intf);
         retval = usb_hub_set_port_power(hdev, hub, port1, true);
         msleep(hub_power_on_good_delay(hub));
-        if (port_dev->child && !retval) {
+        if (udev && !retval) {
                 /*
                  * Attempt to wait for usb hub port to be reconnected in order
                  * to make the resume procedure successful.  The device may have
@@ -109,6 +110,12 @@ static int usb_port_runtime_resume(struct device *dev)
                         dev_dbg(&port_dev->dev, "can't get reconnection after setting port  power on, status %d\n",
                                         retval);
                 retval = 0;
+
+                /* Force the child awake to revalidate after the power loss. */
+                if (!test_and_set_bit(port1, hub->child_usage_bits)) {
+                        pm_runtime_get_noresume(&port_dev->dev);
+                        pm_request_resume(&udev->dev);
+                }
         }
 
         usb_autopm_put_interface(intf);