PM: Introduce pm_power_off_prepare
Introduce the pm_power_off_prepare() callback that can be registered by the
interested platforms in analogy with pm_idle() and pm_power_off(), used for
preparing the system to power off (needed by ACPI).
This allows us to drop acpi_sysclass and device_acpi that are only defined in
order to register the ACPI power off preparation callback, which is needed by
pm_power_off() registered in a much different way.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/sys.c b/kernel/sys.c
index 18987c7..d40e40a 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -100,6 +100,13 @@
EXPORT_SYMBOL(cad_pid);
/*
+ * If set, this is used for preparing the system to power off.
+ */
+
+void (*pm_power_off_prepare)(void);
+EXPORT_SYMBOL(pm_power_off_prepare);
+
+/*
* Notifier list for kernel code which wants to be called
* at shutdown. This is used to stop any idling DMA operations
* and the like.
@@ -867,6 +874,8 @@
void kernel_power_off(void)
{
kernel_shutdown_prepare(SYSTEM_POWER_OFF);
+ if (pm_power_off_prepare)
+ pm_power_off_prepare();
printk(KERN_EMERG "Power down.\n");
machine_power_off();
}
