USB: change name of spinlock in hcd.c

This patch (as940 renames hcd_data_lock in hcd.c to hcd_urb_list_lock,
which is more descriptive of the lock's job.  It also introduces a
convenient inline routine for testing whether a particular USB device
is a root hub.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/hcd.c

@@ -99,12 +99,17 @@ EXPORT_SYMBOL_GPL (usb_bus_list_lock);
 /* used for controlling access to virtual root hubs */
 static DEFINE_SPINLOCK(hcd_root_hub_lock);
 
-/* used when updating hcd data */
-static DEFINE_SPINLOCK(hcd_data_lock);
+/* used when updating an endpoint's URB list */
+static DEFINE_SPINLOCK(hcd_urb_list_lock);
 
 /* wait queue for synchronous unlinks */
 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 
+static inline int is_root_hub(struct usb_device *udev)
+{
+	return (udev->parent == NULL);
+}
+
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -906,14 +911,13 @@ EXPORT_SYMBOL (usb_calc_bus_time);
 static void urb_unlink(struct usb_hcd *hcd, struct urb *urb)
 {
 	unsigned long		flags;
-	int at_root_hub = (urb->dev == hcd->self.root_hub);
 
 	/* clear all state linking urb to this dev (and hcd) */
-	spin_lock_irqsave (&hcd_data_lock, flags);
+	spin_lock_irqsave(&hcd_urb_list_lock, flags);
 	list_del_init (&urb->urb_list);
-	spin_unlock_irqrestore (&hcd_data_lock, flags);
+	spin_unlock_irqrestore(&hcd_urb_list_lock, flags);
 
-	if (hcd->self.uses_dma && !at_root_hub) {
+	if (hcd->self.uses_dma && !is_root_hub(urb->dev)) {
 		if (usb_pipecontrol (urb->pipe)
 			&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
 			dma_unmap_single (hcd->self.controller, urb->setup_dma,
@@ -955,7 +959,7 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 
 	// FIXME:  verify that quiescing hc works right (RH cleans up)
 
-	spin_lock_irqsave (&hcd_data_lock, flags);
+	spin_lock_irqsave(&hcd_urb_list_lock, flags);
 	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
 			[usb_pipeendpoint(urb->pipe)];
 	if (unlikely (!ep))
@@ -972,7 +976,7 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 		status = -ESHUTDOWN;
 		break;
 	}
-	spin_unlock_irqrestore (&hcd_data_lock, flags);
+	spin_unlock_irqrestore(&hcd_urb_list_lock, flags);
 	if (status) {
 		INIT_LIST_HEAD (&urb->urb_list);
 		usbmon_urb_submit_error(&hcd->self, urb, status);
@@ -986,7 +990,7 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 	urb = usb_get_urb (urb);
 	atomic_inc (&urb->use_count);
 
-	if (urb->dev == hcd->self.root_hub) {
+	if (is_root_hub(urb->dev)) {
 		/* NOTE:  requirement on hub callers (usbfs and the hub
 		 * driver, for now) that URBs' urb->transfer_buffer be
 		 * valid and usb_buffer_{sync,unmap}() not be needed, since
@@ -1043,7 +1047,7 @@ unlink1 (struct usb_hcd *hcd, struct urb *urb)
 {
 	int		value;
 
-	if (urb->dev == hcd->self.root_hub)
+	if (is_root_hub(urb->dev))
 		value = usb_rh_urb_dequeue (hcd, urb);
 	else {
 
@@ -1091,11 +1095,11 @@ int usb_hcd_unlink_urb (struct urb *urb, int status)
 	 * that it was submitted.  But as a rule it can't know whether or
 	 * not it's already been unlinked ... so we respect the reversed
 	 * lock sequence needed for the usb_hcd_giveback_urb() code paths
-	 * (urb lock, then hcd_data_lock) in case some other CPU is now
+	 * (urb lock, then hcd_urb_list_lock) in case some other CPU is now
 	 * unlinking it.
 	 */
 	spin_lock_irqsave (&urb->lock, flags);
-	spin_lock (&hcd_data_lock);
+	spin_lock(&hcd_urb_list_lock);
 
 	sys = &urb->dev->dev;
 	hcd = bus_to_hcd(urb->dev->bus);
@@ -1127,17 +1131,16 @@ int usb_hcd_unlink_urb (struct urb *urb, int status)
 	 * finish unlinking the initial failed usb_set_address()
 	 * or device descriptor fetch.
 	 */
-	if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags)
-	    && hcd->self.root_hub != urb->dev) {
+	if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags) &&
+			!is_root_hub(urb->dev)) {
 		dev_warn (hcd->self.controller, "Unlink after no-IRQ?  "
-			"Controller is probably using the wrong IRQ."
-			"\n");
+			"Controller is probably using the wrong IRQ.\n");
 		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
 	}
 
 	urb->status = status;
 
-	spin_unlock (&hcd_data_lock);
+	spin_unlock(&hcd_urb_list_lock);
 	spin_unlock_irqrestore (&urb->lock, flags);
 
 	retval = unlink1 (hcd, urb);
@@ -1146,7 +1149,7 @@ int usb_hcd_unlink_urb (struct urb *urb, int status)
 	return retval;
 
 done:
-	spin_unlock (&hcd_data_lock);
+	spin_unlock(&hcd_urb_list_lock);
 	spin_unlock_irqrestore (&urb->lock, flags);
 	if (retval != -EIDRM && sys && sys->driver)
 		dev_dbg (sys, "hcd_unlink_urb %p fail %d\n", urb, retval);
@@ -1203,7 +1206,7 @@ void usb_hcd_endpoint_disable (struct usb_device *udev,
 
 	/* ep is already gone from udev->ep_{in,out}[]; no more submits */
 rescan:
-	spin_lock (&hcd_data_lock);
+	spin_lock(&hcd_urb_list_lock);
 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
 		int	tmp;
 
@@ -1211,7 +1214,7 @@ rescan:
 		if (urb->status != -EINPROGRESS)
 			continue;
 		usb_get_urb (urb);
-		spin_unlock (&hcd_data_lock);
+		spin_unlock(&hcd_urb_list_lock);
 
 		spin_lock (&urb->lock);
 		tmp = urb->status;
@@ -1240,7 +1243,7 @@ rescan:
 		/* list contents may have changed */
 		goto rescan;
 	}
-	spin_unlock (&hcd_data_lock);
+	spin_unlock(&hcd_urb_list_lock);
 	local_irq_enable ();
 
 	/* synchronize with the hardware, so old configuration state
@@ -1257,7 +1260,7 @@ rescan:
 	 * endpoint_disable methods.
 	 */
 	while (!list_empty (&ep->urb_list)) {
-		spin_lock_irq (&hcd_data_lock);
+		spin_lock_irq(&hcd_urb_list_lock);
 
 		/* The list may have changed while we acquired the spinlock */
 		urb = NULL;
@@ -1266,7 +1269,7 @@ rescan:
 					urb_list);
 			usb_get_urb (urb);
 		}
-		spin_unlock_irq (&hcd_data_lock);
+		spin_unlock_irq(&hcd_urb_list_lock);
 
 		if (urb) {
 			usb_kill_urb (urb);