1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 92aa54550e84..ad0f8f5f6ea1 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -1435,7 +1435,7 @@ static int __devinit su_probe(struct platform_device *op)
 
         rp = &op->resource[0];
         up->port.mapbase = rp->start;
-        up->reg_size = (rp->end - rp->start) + 1;
+        up->reg_size = resource_size(rp);
         up->port.membase = of_ioremap(rp, 0, up->reg_size, "su");
         if (!up->port.membase) {
                 if (type != SU_PORT_PORT)