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>

1 files changed, 26 insertions, 23 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 032b118c2883..42ef1d5f6c8a 100644
--- a/drivers/usb/core/hcd.c
+++ b/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);