From: Stefan Richter <stefanr@s5r6.in-berlin.de>
Date: Tue, 17 Jul 2007 00:10:16 +0000 (+0200)
Subject: firewire: optimize fw_core_add_address_handler
X-Git-Tag: v2.6.24-rc1~825^2~15
X-Git-Url: http://ftp.safe.ca/?a=commitdiff_plain;h=1415d9189e8c59aa9c77a3bba419dcea062c145f;p=safe%2Fjmp%2Flinux-2.6

firewire: optimize fw_core_add_address_handler

Potentially avoids unnecessary loop runs.
Guarantee quadlet-aligned starts of address regions.
Document the return values.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---

diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 3e1cb12..9959b79 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -410,7 +410,12 @@ EXPORT_SYMBOL(fw_unit_space_region);
  * controller.  When a request is received that falls within the
  * specified address range, the specified callback is invoked.  The
  * parameters passed to the callback give the details of the
- * particular request
+ * particular request.
+ *
+ * Return value:  0 on success, non-zero otherwise.
+ * The start offset of the handler's address region is determined by
+ * fw_core_add_address_handler() and is returned in handler->offset.
+ * The offset is quadlet-aligned.
  */
 int
 fw_core_add_address_handler(struct fw_address_handler *handler,
@@ -422,14 +427,15 @@ fw_core_add_address_handler(struct fw_address_handler *handler,
 
 	spin_lock_irqsave(&address_handler_lock, flags);
 
-	handler->offset = region->start;
+	handler->offset = roundup(region->start, 4);
 	while (handler->offset + handler->length <= region->end) {
 		other =
 		    lookup_overlapping_address_handler(&address_handler_list,
 						       handler->offset,
 						       handler->length);
 		if (other != NULL) {
-			handler->offset += other->length;
+			handler->offset =
+			    roundup(other->offset + other->length, 4);
 		} else {
 			list_add_tail(&handler->link, &address_handler_list);
 			ret = 0;