4 files changed, 75 insertions, 37 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 593386eb974d..631f30582481 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -932,6 +932,7 @@ static int autosuspend_check(struct usb_device *udev)
 {
         int                     i;
         struct usb_interface    *intf;
+        long                    suspend_time;
 
         /* For autosuspend, fail fast if anything is in use or autosuspend
          * is disabled.  Also fail if any interfaces require remote wakeup
@@ -943,6 +944,7 @@ static int autosuspend_check(struct usb_device *udev)
         if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
                 return -EPERM;
 
+        suspend_time = udev->last_busy + udev->autosuspend_delay;
         if (udev->actconfig) {
                 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
                         intf = udev->actconfig->interface[i];
@@ -958,6 +960,17 @@ static int autosuspend_check(struct usb_device *udev)
                         }
                 }
         }
+
+        /* If everything is okay but the device hasn't been idle for long
+         * enough, queue a delayed autosuspend request.
+         */
+        suspend_time -= jiffies;
+        if (suspend_time > 0) {
+                if (!timer_pending(&udev->autosuspend.timer))
+                        queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
+                                        suspend_time);
+                return -EAGAIN;
+        }
         return 0;
 }
 
@@ -1010,19 +1023,18 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
         struct usb_interface    *intf;
         struct usb_device       *parent = udev->parent;
 
-        cancel_delayed_work(&udev->autosuspend);
-        if (udev->state == USB_STATE_NOTATTACHED)
-                return 0;
-        if (udev->state == USB_STATE_SUSPENDED)
-                return 0;
+        if (udev->state == USB_STATE_NOTATTACHED ||
+                        udev->state == USB_STATE_SUSPENDED)
+                goto done;
 
         udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
 
         if (udev->auto_pm) {
                 status = autosuspend_check(udev);
                 if (status < 0)
-                        return status;
+                        goto done;
         }
+        cancel_delayed_work(&udev->autosuspend);
 
         /* Suspend all the interfaces and then udev itself */
         if (udev->actconfig) {
@@ -1047,6 +1059,7 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
         } else if (parent)
                 usb_autosuspend_device(parent);
 
+ done:
         // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status);
         return status;
 }
@@ -1086,14 +1099,18 @@ static int usb_resume_both(struct usb_device *udev)
         struct usb_interface    *intf;
         struct usb_device       *parent = udev->parent;
 
-        if (udev->auto_pm && udev->autoresume_disabled)
-                return -EPERM;
         cancel_delayed_work(&udev->autosuspend);
-        if (udev->state == USB_STATE_NOTATTACHED)
-                return -ENODEV;
+        if (udev->state == USB_STATE_NOTATTACHED) {
+                status = -ENODEV;
+                goto done;
+        }
 
         /* Propagate the resume up the tree, if necessary */
         if (udev->state == USB_STATE_SUSPENDED) {
+                if (udev->auto_pm && udev->autoresume_disabled) {
+                        status = -EPERM;
+                        goto done;
+                }
                 if (parent) {
                         status = usb_autoresume_device(parent);
                         if (status == 0) {
@@ -1139,24 +1156,13 @@ static int usb_resume_both(struct usb_device *udev)
                 }
         }
 
+ done:
         // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status);
         return status;
 }
 
 #ifdef CONFIG_USB_SUSPEND
 
-/* usb_autosuspend_work - callback routine to autosuspend a USB device */
-void usb_autosuspend_work(struct work_struct *work)
-{
-        struct usb_device *udev =
-                container_of(work, struct usb_device, autosuspend.work);
-
-        usb_pm_lock(udev);
-        udev->auto_pm = 1;
-        usb_suspend_both(udev, PMSG_SUSPEND);
-        usb_pm_unlock(udev);
-}
-
 /* Internal routine to adjust a device's usage counter and change
  * its autosuspend state.
  */
@@ -1165,20 +1171,34 @@ static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
         int     status = 0;
 
         usb_pm_lock(udev);
+        udev->auto_pm = 1;
         udev->pm_usage_cnt += inc_usage_cnt;
         WARN_ON(udev->pm_usage_cnt < 0);
         if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
-                udev->auto_pm = 1;
-                status = usb_resume_both(udev);
+                if (udev->state == USB_STATE_SUSPENDED)
+                        status = usb_resume_both(udev);
                 if (status != 0)
                         udev->pm_usage_cnt -= inc_usage_cnt;
-        } else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0)
-                queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
-                                udev->autosuspend_delay);
+                else if (inc_usage_cnt)
+                        udev->last_busy = jiffies;
+        } else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
+                if (inc_usage_cnt)
+                        udev->last_busy = jiffies;
+                status = usb_suspend_both(udev, PMSG_SUSPEND);
+        }
         usb_pm_unlock(udev);
         return status;
 }
 
+/* usb_autosuspend_work - callback routine to autosuspend a USB device */
+void usb_autosuspend_work(struct work_struct *work)
+{
+        struct usb_device *udev =
+                container_of(work, struct usb_device, autosuspend.work);
+
+        usb_autopm_do_device(udev, 0);
+}
+
 /**
  * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
  * @udev: the usb_device to autosuspend
@@ -1270,15 +1290,20 @@ static int usb_autopm_do_interface(struct usb_interface *intf,
         if (intf->condition == USB_INTERFACE_UNBOUND)
                 status = -ENODEV;
         else {
+                udev->auto_pm = 1;
                 intf->pm_usage_cnt += inc_usage_cnt;
                 if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
-                        udev->auto_pm = 1;
-                        status = usb_resume_both(udev);
+                        if (udev->state == USB_STATE_SUSPENDED)
+                                status = usb_resume_both(udev);
                         if (status != 0)
                                 intf->pm_usage_cnt -= inc_usage_cnt;
-                } else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0)
-                        queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
-                                        udev->autosuspend_delay);
+                        else if (inc_usage_cnt)
+                                udev->last_busy = jiffies;
+                } else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) {
+                        if (inc_usage_cnt)
+                                udev->last_busy = jiffies;
+                        status = usb_suspend_both(udev, PMSG_SUSPEND);
+                }
         }
         usb_pm_unlock(udev);
         return status;
@@ -1337,11 +1362,14 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
  * or @intf is unbound.  A typical example would be a character-device
  * driver when its device file is opened.
  *
- * The routine increments @intf's usage counter.  So long as the counter
- * is greater than 0, autosuspend will not be allowed for @intf or its
- * usb_device.  When the driver is finished using @intf it should call
- * usb_autopm_put_interface() to decrement the usage counter and queue
- * a delayed autosuspend request (if the counter is <= 0).
+ *
+ * The routine increments @intf's usage counter.  (However if the
+ * autoresume fails then the counter is re-decremented.)  So long as the
+ * counter is greater than 0, autosuspend will not be allowed for @intf
+ * or its usb_device.  When the driver is finished using @intf it should
+ * call usb_autopm_put_interface() to decrement the usage counter and
+ * queue a delayed autosuspend request (if the counter is <= 0).
+ *
  *
  * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
  * core will not change its value other than the increment and decrement
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 8bc3ce6d9666..40cf882293e6 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1306,6 +1306,7 @@ static void hcd_resume_work(struct work_struct *work)
         struct usb_device *udev = hcd->self.root_hub;
 
         usb_lock_device(udev);
+        usb_mark_last_busy(udev);
         usb_external_resume_device(udev);
         usb_unlock_device(udev);
 }
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2a0b15e42bc7..bde29ab2b504 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1859,6 +1859,7 @@ static int remote_wakeup(struct usb_device *udev)
         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);
diff --git a/include/linux/usb.h b/include/linux/usb.h
index f9e4445d5b53..cfbd2bb8fa2c 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -398,6 +398,7 @@ struct usb_device {
         struct delayed_work autosuspend; /* for delayed autosuspends */
         struct mutex pm_mutex;          /* protects PM operations */
 
+        unsigned long last_busy;        /* time of last use */
         int autosuspend_delay;          /* in jiffies */
 
         unsigned auto_pm:1;             /* autosuspend/resume in progress */
@@ -443,6 +444,11 @@ static inline void usb_autopm_disable(struct usb_interface *intf)
         usb_autopm_set_interface(intf);
 }
 
+static inline void usb_mark_last_busy(struct usb_device *udev)
+{
+        udev->last_busy = jiffies;
+}
+
 #else
 
 static inline int usb_autopm_set_interface(struct usb_interface *intf)
@@ -457,6 +463,8 @@ static inline void usb_autopm_enable(struct usb_interface *intf)
 { }
 static inline void usb_autopm_disable(struct usb_interface *intf)
 { }
+static inline void usb_mark_last_busy(struct usb_device *udev)
+{ }
 #endif
 
 /*-------------------------------------------------------------------------*/