diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 5e569fa9b87b..01c8c97c15b7 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -1131,21 +1131,20 @@ static int skip_isa_ioresource_align(struct pci_dev *dev)
  * but we want to try to avoid allocating at 0x2900-0x2bff
  * which might have be mirrored at 0x0100-0x03ff..
  */
-void pcibios_align_resource(void *data, struct resource *res,
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 				resource_size_t size, resource_size_t align)
 {
 	struct pci_dev *dev = data;
+	resource_size_t start = res->start;
 
 	if (res->flags & IORESOURCE_IO) {
-		resource_size_t start = res->start;
-
 		if (skip_isa_ioresource_align(dev))
-			return;
-		if (start & 0x300) {
+			return start;
+		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
-			res->start = start;
-		}
 	}
+
+	return start;
 }
 EXPORT_SYMBOL(pcibios_align_resource);