firewire: use bitwise and to get reg in handle_registers

for code efficiency.

Signed-off-by: Jarod Wilson <jwilson@redhat.com>
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 47bfe76..3682e75 100644 (file)
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -797,7 +797,7 @@ handle_registers(struct fw_card *card, struct fw_request *request,
                 unsigned long long offset,
                 void *payload, size_t length, void *callback_data)
 {
-       int reg = offset - CSR_REGISTER_BASE;
+       int reg = offset & ~CSR_REGISTER_BASE;
        unsigned long long bus_time;
        __be32 *data = payload;