Pull bugfix into test branch

Conflicts:

	kernel/power/disk.c
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 0b00f56..88fc5d7 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -60,9 +60,11 @@
 {
 	switch(mode) {
 	case PM_DISK_PLATFORM:
-		kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
-		pm_ops->enter(PM_SUSPEND_DISK);
-		break;
+		if (pm_ops && pm_ops->enter) {
+			kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
+			pm_ops->enter(PM_SUSPEND_DISK);
+			break;
+		}
 	case PM_DISK_SHUTDOWN:
 		kernel_power_off();
 		break;