On 10/09/2014 03:32 AM, Pavel Machek wrote:

On Mon 2014-10-06 22:28:05, Guenter Roeck wrote:

quoted

Poweroff handlers may now be installed with register_poweroff_handler.
Use the new API function have_kernel_poweroff to determine if a poweroff
handler has been installed.

Cc: Rafael J. Wysocki <redacted>
Cc: Pavel Machek <redacted>
Cc: Len Brown <redacted>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
  kernel/power/hibernate.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a9dfa79..20353c5 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c

@@ -602,7 +602,7 @@ static void power_down(void)
  	case HIBERNATION_PLATFORM:
  		hibernation_platform_enter();
  	case HIBERNATION_SHUTDOWN:
-		if (pm_power_off)
+		if (have_kernel_poweroff())
  			kernel_power_off();
  		break;

poweroff -> power_off.

As mentioned in my other reply, that was on purpose to distinguish
existing functions from poweroff handler functions.

But if you are playing with this, anyway... does it make sense to
introduce kernel_power_off() that just works, no need to check
have_..?
									Pavel

I am trying not to change existing behavior.

kernel_power_off is an existing function which does some cleanup
before calling machine_power_off which in turn calls do_kernel_poweroff
(or currently pm_power_off and may do some other machine specific stuff.

Sure, poweroff handling could be unified further. We could decide to
enter an endless loop if machine_power_off() returns, or we could decide
to dump a warning or panic in this case. But that is all separate from
the issue I am trying to solve here, which is to provide a capability to
register more than one poweroff handler. It would also not be that simple,
since some architectures call machine_power_off() directly from various
places.

Guenter