diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index ab1e366..54b6ac2 100644
--- a/drivers/usb/host/ohci-sm501.c
+++ b/drivers/usb/host/ohci-sm501.c
@@ -199,7 +199,8 @@
 	usb_put_hcd(hcd);
 	dma_release_declared_memory(&pdev->dev);
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	release_mem_region(mem->start, mem->end - mem->start + 1);
+	if (mem)
+		release_mem_region(mem->start, mem->end - mem->start + 1);
 
 	/* mask interrupts and disable power */