Merge commit 'v2.6.28-rc6' into core/debug

1 files changed, 40 insertions, 7 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 8abd4e59bf4..e1b42626d04 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -81,6 +81,10 @@
 
 /*-------------------------------------------------------------------------*/
 
+/* Keep track of which host controller drivers are loaded */
+unsigned long usb_hcds_loaded;
+EXPORT_SYMBOL_GPL(usb_hcds_loaded);
+
 /* host controllers we manage */
 LIST_HEAD (usb_bus_list);
 EXPORT_SYMBOL_GPL (usb_bus_list);
@@ -102,6 +106,9 @@ static DEFINE_SPINLOCK(hcd_root_hub_lock);
 /* used when updating an endpoint's URB list */
 static DEFINE_SPINLOCK(hcd_urb_list_lock);
 
+/* used to protect against unlinking URBs after the device is gone */
+static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
+
 /* wait queue for synchronous unlinks */
 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 
@@ -818,9 +825,8 @@ static int usb_register_bus(struct usb_bus *bus)
 	set_bit (busnum, busmap.busmap);
 	bus->busnum = busnum;
 
-	bus->dev = device_create_drvdata(usb_host_class, bus->controller,
-					 MKDEV(0, 0), bus,
-					 "usb_host%d", busnum);
+	bus->dev = device_create(usb_host_class, bus->controller, MKDEV(0, 0),
+				 bus, "usb_host%d", busnum);
 	result = PTR_ERR(bus->dev);
 	if (IS_ERR(bus->dev))
 		goto error_create_class_dev;
@@ -1373,10 +1379,25 @@ static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
 int usb_hcd_unlink_urb (struct urb *urb, int status)
 {
 	struct usb_hcd		*hcd;
-	int			retval;
+	int			retval = -EIDRM;
+	unsigned long		flags;
 
-	hcd = bus_to_hcd(urb->dev->bus);
-	retval = unlink1(hcd, urb, status);
+	/* Prevent the device and bus from going away while
+	 * the unlink is carried out.  If they are already gone
+	 * then urb->use_count must be 0, since disconnected
+	 * devices can't have any active URBs.
+	 */
+	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
+	if (atomic_read(&urb->use_count) > 0) {
+		retval = 0;
+		usb_get_dev(urb->dev);
+	}
+	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
+	if (retval == 0) {
+		hcd = bus_to_hcd(urb->dev->bus);
+		retval = unlink1(hcd, urb, status);
+		usb_put_dev(urb->dev);
+	}
 
 	if (retval == 0)
 		retval = -EINPROGRESS;
@@ -1525,6 +1546,17 @@ void usb_hcd_disable_endpoint(struct usb_device *udev,
 		hcd->driver->endpoint_disable(hcd, ep);
 }
 
+/* Protect against drivers that try to unlink URBs after the device
+ * is gone, by waiting until all unlinks for @udev are finished.
+ * Since we don't currently track URBs by device, simply wait until
+ * nothing is running in the locked region of usb_hcd_unlink_urb().
+ */
+void usb_hcd_synchronize_unlinks(struct usb_device *udev)
+{
+	spin_lock_irq(&hcd_urb_unlink_lock);
+	spin_unlock_irq(&hcd_urb_unlink_lock);
+}
+
 /*-------------------------------------------------------------------------*/
 
 /* called in any context */
@@ -1876,7 +1908,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
 		 * interrupts we can remove it here.
 		 */
-		irqflags &= ~IRQF_DISABLED;
+		if (irqflags & IRQF_SHARED)
+			irqflags &= ~IRQF_DISABLED;
 
 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
 				hcd->driver->description, hcd->self.busnum);