diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index 924d794..95be9e9 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -1338,7 +1338,7 @@
 	}
 
 	info->regs_res = request_mem_region(res->start,
-					    res->end - res->start,
+					    resource_size(res),
 					    pdev->name);
 
 	if (info->regs_res == NULL) {
@@ -1347,7 +1347,7 @@
 		goto err_release;
 	}
 
-	info->regs = ioremap(res->start, (res->end - res->start)+1);
+	info->regs = ioremap(res->start, resource_size(res));
 	if (info->regs == NULL) {
 		dev_err(dev, "cannot remap registers\n");
 		ret = -ENXIO;
@@ -1363,7 +1363,7 @@
 	}
 
 	info->fbmem_res = request_mem_region(res->start,
-					     (res->end - res->start)+1,
+					     resource_size(res),
 					     pdev->name);
 	if (info->fbmem_res == NULL) {
 		dev_err(dev, "cannot claim framebuffer\n");
@@ -1371,13 +1371,13 @@
 		goto err_regs_map;
 	}
 
-	info->fbmem = ioremap(res->start, (res->end - res->start)+1);
+	info->fbmem = ioremap(res->start, resource_size(res));
 	if (info->fbmem == NULL) {
 		dev_err(dev, "cannot remap framebuffer\n");
 		goto err_mem_res;
 	}
 
-	info->fbmem_len = (res->end - res->start)+1;
+	info->fbmem_len = resource_size(res);
 
 	/* clear framebuffer memory - avoids garbage data on unused fb */
 	memset(info->fbmem, 0, info->fbmem_len);