[PATCH] suspend: cleanup calling of power off methods.

In the lead up to 2.6.13 I fixed a large number of reboot problems by
making the calling conventions consistent.  Despite checking and double
checking my work it appears I missed an obvious one.

The S4 suspend code for PM_DISK_PLATFORM was also calling device_shutdown
without setting system_state, and was not calling the appropriate
reboot_notifier.

This patch fixes the bug by replacing the call of device_suspend with
kernel_poweroff_prepare.

Various forms of this failure have been fixed and tracked for a while.

Thanks for tracking this down go to: Alexey Starikovskiy, Meelis Roos
<mroos@linux.ee>, Nigel Cunningham <ncunningham@cyclades.com>, Pierre
Ossman <drzeus-list@drzeus.cx>

History of this bug is at:
http://bugme.osdl.org/show_bug.cgi?id=4320Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/power/disk.c

@@ -17,12 +17,12 @@
 #include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/pm.h>
 
 #include "power.h"
 
 
 extern suspend_disk_method_t pm_disk_mode;
-extern struct pm_ops * pm_ops;
 
 extern int swsusp_suspend(void);
 extern int swsusp_write(void);
@@ -49,13 +49,11 @@ dev_t swsusp_resume_device;
 
 static void power_down(suspend_disk_method_t mode)
 {
-	unsigned long flags;
 	int error = 0;
 
-	local_irq_save(flags);
 	switch(mode) {
 	case PM_DISK_PLATFORM:
- 		device_shutdown();
+		kernel_power_off_prepare();
 		error = pm_ops->enter(PM_SUSPEND_DISK);
 		break;
 	case PM_DISK_SHUTDOWN: