3 files changed, 52 insertions, 21 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 09a53e7f3327..42a436478b78 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -924,6 +924,15 @@ static int register_root_hub(struct usb_hcd *hcd)
 	return retval;
 }
 
+void usb_enable_root_hub_irq (struct usb_bus *bus)
+{
+	struct usb_hcd *hcd;
+
+	hcd = container_of (bus, struct usb_hcd, self);
+	if (hcd->driver->hub_irq_enable && hcd->state != HC_STATE_HALT)
+		hcd->driver->hub_irq_enable (hcd);
+}
+
 
 /*-------------------------------------------------------------------------*/
 
@@ -1684,19 +1693,30 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum);
 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
 {
 	struct usb_hcd		*hcd = __hcd;
-	int			start = hcd->state;
+	unsigned long		flags;
+	irqreturn_t		rc;
 
-	if (unlikely(start == HC_STATE_HALT ||
-	    !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
-		return IRQ_NONE;
-	if (hcd->driver->irq (hcd) == IRQ_NONE)
-		return IRQ_NONE;
+	/* IRQF_DISABLED doesn't work correctly with shared IRQs
+	 * when the first handler doesn't use it.  So let's just
+	 * assume it's never used.
+	 */
+	local_irq_save(flags);
 
-	set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+	if (unlikely(hcd->state == HC_STATE_HALT ||
+		     !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
+		rc = IRQ_NONE;
+	} else if (hcd->driver->irq(hcd) == IRQ_NONE) {
+		rc = IRQ_NONE;
+	} else {
+		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+
+		if (unlikely(hcd->state == HC_STATE_HALT))
+			usb_hc_died(hcd);
+		rc = IRQ_HANDLED;
+	}
 
-	if (unlikely(hcd->state == HC_STATE_HALT))
-		usb_hc_died (hcd);
-	return IRQ_HANDLED;
+	local_irq_restore(flags);
+	return rc;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -1860,6 +1880,13 @@ int usb_add_hcd(struct usb_hcd *hcd,
 
 	/* enable irqs just before we start the controller */
 	if (hcd->driver->irq) {
+
+		/* IRQF_DISABLED doesn't work as advertised when used together
+		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
+		 * interrupts we can remove it here.
+		 */
+		irqflags &= ~IRQF_DISABLED;
+
 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
 				hcd->driver->description, hcd->self.busnum);
 		if ((retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index a0bf5df6cb6f..b9de1569b39e 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -210,6 +210,8 @@ struct hc_driver {
 	int	(*bus_suspend)(struct usb_hcd *);
 	int	(*bus_resume)(struct usb_hcd *);
 	int	(*start_port_reset)(struct usb_hcd *, unsigned port_num);
+	void	(*hub_irq_enable)(struct usb_hcd *);
+		/* Needed only if port-change IRQs are level-triggered */
 
 		/* force handover of high-speed port to full-speed companion */
 	void	(*relinquish_port)(struct usb_hcd *, int);
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 94789be54ca3..4cfe32a16c37 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -713,18 +713,11 @@ static void hub_restart(struct usb_hub *hub, int type)
 		}
 
 		/* Was the power session lost while we were suspended? */
-		switch (type) {
-		case HUB_RESET_RESUME:
-			portstatus = 0;
-			portchange = USB_PORT_STAT_C_CONNECTION;
-			break;
+		status = hub_port_status(hub, port1, &portstatus, &portchange);
 
-		case HUB_RESET:
-		case HUB_RESUME:
-			status = hub_port_status(hub, port1,
-					&portstatus, &portchange);
-			break;
-		}
+		/* If the device is gone, khubd will handle it later */
+		if (status == 0 && !(portstatus & USB_PORT_STAT_CONNECTION))
+			continue;
 
 		/* For "USB_PERSIST"-enabled children we must
 		 * mark the child device for reset-resume and
@@ -2080,6 +2073,8 @@ int usb_port_resume(struct usb_device *udev)
 	}
 
 	clear_bit(port1, hub->busy_bits);
+	if (!hub->hdev->parent && !hub->busy_bits[0])
+		usb_enable_root_hub_irq(hub->hdev->bus);
 
 	if (status == 0)
 		status = finish_port_resume(udev);
@@ -3009,6 +3004,11 @@ static void hub_events(void)
 
 		hub->activating = 0;
 
+		/* If this is a root hub, tell the HCD it's okay to
+		 * re-enable port-change interrupts now. */
+		if (!hdev->parent && !hub->busy_bits[0])
+			usb_enable_root_hub_irq(hdev->bus);
+
 loop_autopm:
 		/* Allow autosuspend if we're not going to run again */
 		if (list_empty(&hub->event_list))
@@ -3234,6 +3234,8 @@ int usb_reset_device(struct usb_device *udev)
 			break;
 	}
 	clear_bit(port1, parent_hub->busy_bits);
+	if (!parent_hdev->parent && !parent_hub->busy_bits[0])
+		usb_enable_root_hub_irq(parent_hdev->bus);
 
 	if (ret < 0)
 		goto re_enumerate;