USB: prepare for changover to Runtime PM framework

This patch (as1303) revises the USB Power Management infrastructure to
make it compatible with the new driver-model Runtime PM framework:

	Drivers are no longer allowed to access intf->pm_usage_cnt
	directly; the PM framework manages its own usage counters.

	usb_autopm_set_interface() is eliminated, because it directly
	sets intf->pm_usage_cnt.

	usb_autopm_enable() and usb_autopm_disable() are eliminated,
	because they call usb_autopm_set_interface().

	usb_autopm_get_interface_no_resume() and
	usb_autopm_put_interface_no_suspend() are added.  They
	correspond to pm_runtime_get_noresume() and
	pm_runtime_put_noidle() in the PM framework.

	The power/level attribute no longer accepts "suspend", only
	"on" and "auto".  The PM framework doesn't allow devices to be
	forced into a suspended mode.

The hub driver contains the only code that violates the new
guidelines.  It is updated to use the new interface routines instead.

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

1 files changed, 32 insertions, 13 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 5413d712cae..b38fd6730e2 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -71,6 +71,7 @@ struct usb_hub {
 
 	unsigned		mA_per_port;	/* current for each child */
 
+	unsigned		init_done:1;
 	unsigned		limited_power:1;
 	unsigned		quiescing:1;
 	unsigned		disconnected:1;
@@ -375,12 +376,13 @@ static void kick_khubd(struct usb_hub *hub)
 {
 	unsigned long	flags;
 
-	/* Suppress autosuspend until khubd runs */
-	atomic_set(&to_usb_interface(hub->intfdev)->pm_usage_cnt, 1);
-
 	spin_lock_irqsave(&hub_event_lock, flags);
 	if (!hub->disconnected && list_empty(&hub->event_list)) {
 		list_add_tail(&hub->event_list, &hub_event_list);
+
+		/* Suppress autosuspend until khubd runs */
+		usb_autopm_get_interface_no_resume(
+				to_usb_interface(hub->intfdev));
 		wake_up(&khubd_wait);
 	}
 	spin_unlock_irqrestore(&hub_event_lock, flags);
@@ -665,7 +667,7 @@ int usb_remove_device(struct usb_device *udev)
 }
 
 enum hub_activation_type {
-	HUB_INIT, HUB_INIT2, HUB_INIT3,
+	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
 	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
 };
 
@@ -710,8 +712,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 					msecs_to_jiffies(delay));
 
 			/* Suppress autosuspend until init is done */
-			atomic_set(&to_usb_interface(hub->intfdev)->
-					pm_usage_cnt, 1);
+			usb_autopm_get_interface_no_resume(
+					to_usb_interface(hub->intfdev));
 			return;		/* Continues at init2: below */
 		} else {
 			hub_power_on(hub, true);
@@ -818,6 +820,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 	}
  init3:
 	hub->quiescing = 0;
+	hub->init_done = 1;
 
 	status = usb_submit_urb(hub->urb, GFP_NOIO);
 	if (status < 0)
@@ -827,6 +830,10 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 
 	/* Scan all ports that need attention */
 	kick_khubd(hub);
+
+	/* Allow autosuspend if it was suppressed */
+	if (type <= HUB_INIT3)
+		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
 }
 
 /* Implement the continuations for the delays above */
@@ -854,6 +861,11 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
 	int i;
 
 	cancel_delayed_work_sync(&hub->init_work);
+	if (!hub->init_done) {
+		hub->init_done = 1;
+		usb_autopm_put_interface_no_suspend(
+				to_usb_interface(hub->intfdev));
+	}
 
 	/* khubd and related activity won't re-trigger */
 	hub->quiescing = 1;
@@ -1176,7 +1188,10 @@ static void hub_disconnect(struct usb_interface *intf)
 
 	/* Take the hub off the event list and don't let it be added again */
 	spin_lock_irq(&hub_event_lock);
-	list_del_init(&hub->event_list);
+	if (!list_empty(&hub->event_list)) {
+		list_del_init(&hub->event_list);
+		usb_autopm_put_interface_no_suspend(intf);
+	}
 	hub->disconnected = 1;
 	spin_unlock_irq(&hub_event_lock);
 
@@ -3235,7 +3250,7 @@ static void hub_events(void)
 		 * disconnected while waiting for the lock to succeed. */
 		usb_lock_device(hdev);
 		if (unlikely(hub->disconnected))
-			goto loop;
+			goto loop2;
 
 		/* If the hub has died, clean up after it */
 		if (hdev->state == USB_STATE_NOTATTACHED) {
@@ -3384,11 +3399,15 @@ static void hub_events(void)
 			}
 		}
 
-loop_autopm:
-		/* Allow autosuspend if we're not going to run again */
-		if (list_empty(&hub->event_list))
-			usb_autopm_enable(intf);
-loop:
+ loop_autopm:
+		/* Balance the usb_autopm_get_interface() above */
+		usb_autopm_put_interface_no_suspend(intf);
+ loop:
+		/* Balance the usb_autopm_get_interface_no_resume() in
+		 * kick_khubd() and allow autosuspend.
+		 */
+		usb_autopm_put_interface(intf);
+ loop2:
 		usb_unlock_device(hdev);
 		kref_put(&hub->kref, hub_release);