diff --git a/drivers/ide/au1xxx-ide.c b/drivers/ide/au1xxx-ide.c
index 58121bd..87cef0c 100644
--- a/drivers/ide/au1xxx-ide.c
+++ b/drivers/ide/au1xxx-ide.c
@@ -532,14 +532,13 @@
 		goto out;
 	}
 
-	if (!request_mem_region(res->start, res->end - res->start + 1,
-				dev->name)) {
+	if (!request_mem_region(res->start, resource_size(res), dev->name)) {
 		pr_debug("%s: request_mem_region failed\n", DRV_NAME);
 		ret =  -EBUSY;
 		goto out;
 	}
 
-	ahwif->regbase = (u32)ioremap(res->start, res->end - res->start + 1);
+	ahwif->regbase = (u32)ioremap(res->start, resource_size(res));
 	if (ahwif->regbase == 0) {
 		ret = -ENOMEM;
 		goto out;
@@ -575,7 +574,7 @@
 	iounmap((void *)ahwif->regbase);
 
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
-	release_mem_region(res->start, res->end - res->start + 1);
+	release_mem_region(res->start, resource_size(res));
 
 	return 0;
 }