[PATCH] USB: Fix locking for USB suspend/resume

The earlier USB locking updates didn't touch the suspend/resume
routines.  They need updating as well, since now the caller holds the
device semaphore.  This patch (as608) makes the necessary changes.  It
also adds a line to store the correct power state when a device is
resumed, something which was unaccountably missing.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 39 insertions, 15 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 02601f412f9d..895ac829b9cf 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1648,15 +1648,22 @@ static int __usb_suspend_device (struct usb_device *udev, int port1)
 int usb_suspend_device(struct usb_device *udev)
 {
 #ifdef  CONFIG_USB_SUSPEND
-        int     port1, status;
+        int     port1;
 
-        port1 = locktree(udev);
-        if (port1 < 0)
-                return port1;
+        if (udev->state == USB_STATE_NOTATTACHED)
+                return -ENODEV;
+        if (!udev->parent)
+                port1 = 0;
+        else {
+                for (port1 = udev->parent->maxchild; port1 > 0; --port1) {
+                        if (udev->parent->children[port1-1] == udev)
+                                break;
+                }
+                if (port1 == 0)
+                        return -ENODEV;
+        }
 
-        status = __usb_suspend_device(udev, port1);
-        usb_unlock_device(udev);
-        return status;
+        return __usb_suspend_device(udev, port1);
 #else
         /* NOTE:  udev->state unchanged, it's not lying ... */
         udev->dev.power.power_state = PMSG_SUSPEND;
@@ -1688,6 +1695,7 @@ static int finish_device_resume(struct usb_device *udev)
         usb_set_device_state(udev, udev->actconfig
                         ? USB_STATE_CONFIGURED
                         : USB_STATE_ADDRESS);
+        udev->dev.power.power_state = PMSG_ON;
 
         /* 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,
@@ -1723,8 +1731,14 @@ static int finish_device_resume(struct usb_device *udev)
                  * may have a child resume event to deal with soon
                  */
                 resume = udev->dev.bus->resume;
-                for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++)
-                        (void) resume(&udev->actconfig->interface[i]->dev);
+                for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
+                        struct device *dev =
+                                        &udev->actconfig->interface[i]->dev;
+
+                        down(&dev->sem);
+                        (void) resume(dev);
+                        up(&dev->sem);
+                }
                 status = 0;
 
         } else if (udev->devnum <= 0) {
@@ -1809,9 +1823,18 @@ int usb_resume_device(struct usb_device *udev)
 {
         int     port1, status;
 
-        port1 = locktree(udev);
-        if (port1 < 0)
-                return port1;
+        if (udev->state == USB_STATE_NOTATTACHED)
+                return -ENODEV;
+        if (!udev->parent)
+                port1 = 0;
+        else {
+                for (port1 = udev->parent->maxchild; port1 > 0; --port1) {
+                        if (udev->parent->children[port1-1] == udev)
+                                break;
+                }
+                if (port1 == 0)
+                        return -ENODEV;
+        }
 
 #ifdef  CONFIG_USB_SUSPEND
         /* selective resume of one downstream hub-to-device port */
@@ -1830,11 +1853,12 @@ int usb_resume_device(struct usb_device *udev)
                 dev_dbg(&udev->dev, "can't resume, status %d\n",
                         status);
 
-        usb_unlock_device(udev);
-
         /* rebind drivers that had no suspend() */
-        if (status == 0)
+        if (status == 0) {
+                usb_unlock_device(udev);
                 bus_rescan_devices(&usb_bus_type);
+                usb_lock_device(udev);
+        }
         return status;
 }