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 @@
* 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 @@
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;