USB: hub: change the locking in hub_activate

BugLink: http://bugs.launchpad.net/bugs/1621113
commit 07d316a22e119fa301fd7dba7f1e1adfd4f72c05 upstream.

The locking in hub_activate() is not adequate to provide full mutual
exclusion with hub_quiesce().  The subroutine locks the hub's
usb_interface, but the callers of hub_quiesce() (such as
hub_pre_reset() and hub_event()) hold the lock to the hub's
usb_device.

This patch changes hub_activate() to make it acquire the same lock as
those other routines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b09f5f4fcc4ee62c9503ef1d3ebf5ee77c94b9bb..4d2646ba073eaf3817816488b553448a9bfec071 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1050,7 +1050,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 
        /* Continue a partial initialization */
        if (type == HUB_INIT2 || type == HUB_INIT3) {
-               device_lock(hub->intfdev);
+               device_lock(&hdev->dev);
 
                /* Was the hub disconnected while we were waiting? */
                if (hub->disconnected)
@@ -1257,7 +1257,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
                        queue_delayed_work(system_power_efficient_wq,
                                        &hub->init_work,
                                        msecs_to_jiffies(delay));
-                       device_unlock(hub->intfdev);
+                       device_unlock(&hdev->dev);
                        return;         /* Continues at init3: below */
                } else {
                        msleep(delay);
@@ -1280,7 +1280,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
                /* Allow autosuspend if it was suppressed */
  disconnected:
                usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
-               device_unlock(hub->intfdev);
+               device_unlock(&hdev->dev);
        }
 
        kref_put(&hub->kref, hub_release);