diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c
index f1b97feada18..30ba2e9a340d 100644
--- a/sys/dev/acpica/acpi_cpu.c
+++ b/sys/dev/acpica/acpi_cpu.c
@@ -94,8 +94,7 @@ struct acpi_cpu_device {
 
 #define PM_USEC(x)	 ((x) >> 2)	/* ~4 clocks per usec (3.57955 Mhz) */
 
-#define ACPI_CPU_NOTIFY_PERF_STATES	0x80	/* _PSS changed. */
-#define ACPI_CPU_NOTIFY_CX_STATES	0x81	/* _CST changed. */
+#define ACPI_NOTIFY_CX_STATES	0x81	/* _CST changed. */
 
 #define CPU_QUIRK_NO_C3		(1<<0)	/* C3-type states are not usable. */
 #define CPU_QUIRK_NO_BM_CTRL	(1<<2)	/* No bus mastering control. */
@@ -848,8 +847,7 @@ acpi_cpu_idle()
 }
 
 /*
- * Re-evaluate the _PSS and _CST objects when we are notified that they
- * have changed.
+ * Re-evaluate the _CST object when we are notified that it changed.
  *
  * XXX Re-evaluation disabled until locking is done.
  */
@@ -858,19 +856,11 @@ acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
 {
     struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
 
-    switch (notify) {
-    case ACPI_CPU_NOTIFY_PERF_STATES:
-	device_printf(sc->cpu_dev, "Performance states changed\n");
-	/* acpi_cpu_px_available(sc); */
-	break;
-    case ACPI_CPU_NOTIFY_CX_STATES:
-	device_printf(sc->cpu_dev, "Cx states changed\n");
-	/* acpi_cpu_cx_cst(sc); */
-	break;
-    default:
-	device_printf(sc->cpu_dev, "Unknown notify %#x\n", notify);
-	break;
-    }
+    if (notify != ACPI_NOTIFY_CX_STATES)
+	return;
+
+    device_printf(sc->cpu_dev, "Cx states changed\n");
+    /* acpi_cpu_cx_cst(sc); */
 }
 
 static int
diff --git a/sys/dev/acpica/acpi_perf.c b/sys/dev/acpica/acpi_perf.c
index b8cd3d7cd4f8..259f68bda454 100644
--- a/sys/dev/acpica/acpi_perf.c
+++ b/sys/dev/acpica/acpi_perf.c
@@ -87,6 +87,8 @@ struct acpi_perf_softc {
 	(bus_space_write_4(rman_get_bustag((reg)), 	\
 	    rman_get_bushandle((reg)), 0, (val)))
 
+#define ACPI_NOTIFY_PERF_STATES		0x80	/* _PSS changed. */
+
 static void	acpi_perf_identify(driver_t *driver, device_t parent);
 static int	acpi_perf_probe(device_t dev);
 static int	acpi_perf_attach(device_t dev);
@@ -144,7 +146,7 @@ acpi_perf_identify(driver_t *driver, device_t parent)
 	if (ACPI_FAILURE(AcpiEvaluateObject(handle, "_PSS", NULL, NULL)))
 		return;
 	if (BUS_ADD_CHILD(parent, 0, "acpi_perf", 0) == NULL)
-		device_printf(parent, "acpi_perf: add child failed\n");
+		device_printf(parent, "add acpi_perf child failed\n");
 }
 
 static int
@@ -322,6 +324,9 @@ acpi_px_notify(ACPI_HANDLE h, UINT32 notify, void *context)
 	struct acpi_perf_softc *sc;
 
 	sc = context;
+	if (notify != ACPI_NOTIFY_PERF_STATES)
+		return;
+
 	acpi_px_available(sc);
 
 	/* TODO: Implement notification when frequency changes. */