Date: Tue, 17 Jul 2007 02:10:16 +0200 (CEST) From: Stefan Richter Subject: 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 --- drivers/firewire/fw-transaction.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) Index: linux-2.6.23-rc1/drivers/firewire/fw-transaction.c =================================================================== --- linux-2.6.23-rc1.orig/drivers/firewire/fw-transaction.c +++ linux-2.6.23-rc1/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_ad 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;