[PATCH RFC] PM / Hibernate: no kernel_power_off when pm_power_off NULL

[Sebastian Capella <sebastian.capella@linaro.org>]

Reboot logic in kernel/reboot will avoid calling kernel_power_off
when pm_power_off is null, and instead uses kernel_halt.  Change
hibernate's power_down to follow the behavior in the reboot call.

Calling the notifier twice (once for SYS_POWER_OFF and again for
SYS_HALT) causes a panic during hibernation on Kirkwood
Openblocks A6 board.

Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org>
Reported-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
---
 kernel/power/hibernate.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 37170d4..6a278dc 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -595,7 +595,8 @@ static void power_down(void)
 	case HIBERNATION_PLATFORM:
 		hibernation_platform_enter();
 	case HIBERNATION_SHUTDOWN:
-		kernel_power_off();
+		if (pm_power_off)
+			kernel_power_off();
 		break;
 #ifdef CONFIG_SUSPEND
 	case HIBERNATION_SUSPEND:
-- 
1.7.9.5