diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 33d0034..9dc5be5 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -551,6 +551,7 @@
 		    xhci_readl(xhci, &xhci->op_regs->status));
 }
 
+#ifdef CONFIG_PM
 static void xhci_save_registers(struct xhci_hcd *xhci)
 {
 	xhci->s3.command = xhci_readl(xhci, &xhci->op_regs->command);
@@ -761,6 +762,13 @@
 	return 0;
 }
 
+#else
+
+#define	xhci_suspend	NULL
+#define	xhci_resume	NULL
+
+#endif	/* CONFIG_PM */
+
 /*-------------------------------------------------------------------------*/
 
 /**