PM / Hibernate: Enable suspend to both for in-kernel hibernation.

It is often useful to suspend to memory after hibernation image has been
written to disk. If the battery runs out or power is otherwise lost, the
computer will resume from the hibernated image. If not, it will resume
from memory and hibernation image will be discarded.

Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 36 insertions, 0 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 8b53db38a279..21ad3fe3164f 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -5,6 +5,7 @@
  * Copyright (c) 2003 Open Source Development Lab
  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
+ * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  *
  * This file is released under the GPLv2.
  */
@@ -46,6 +47,9 @@ enum {
         HIBERNATION_PLATFORM,
         HIBERNATION_SHUTDOWN,
         HIBERNATION_REBOOT,
+#ifdef CONFIG_SUSPEND
+        HIBERNATION_SUSPEND,
+#endif
         /* keep last */
         __HIBERNATION_AFTER_LAST
 };
@@ -574,6 +578,10 @@ int hibernation_platform_enter(void)
  */
 static void power_down(void)
 {
+#ifdef CONFIG_SUSPEND
+        int error;
+#endif
+
         switch (hibernation_mode) {
         case HIBERNATION_REBOOT:
                 kernel_restart(NULL);
@@ -583,6 +591,25 @@ static void power_down(void)
         case HIBERNATION_SHUTDOWN:
                 kernel_power_off();
                 break;
+#ifdef CONFIG_SUSPEND
+        case HIBERNATION_SUSPEND:
+                error = suspend_devices_and_enter(PM_SUSPEND_MEM);
+                if (error) {
+                        if (hibernation_ops)
+                                hibernation_mode = HIBERNATION_PLATFORM;
+                        else
+                                hibernation_mode = HIBERNATION_SHUTDOWN;
+                        power_down();
+                }
+                /*
+                 * Restore swap signature.
+                 */
+                error = swsusp_unmark();
+                if (error)
+                        printk(KERN_ERR "PM: Swap will be unusable! "
+                                        "Try swapon -a.\n");
+                return;
+#endif
         }
         kernel_halt();
         /*
@@ -827,6 +854,9 @@ static const char * const hibernation_modes[] = {
         [HIBERNATION_PLATFORM]  = "platform",
         [HIBERNATION_SHUTDOWN]  = "shutdown",
         [HIBERNATION_REBOOT]    = "reboot",
+#ifdef CONFIG_SUSPEND
+        [HIBERNATION_SUSPEND]   = "suspend",
+#endif
 };
 
 /*
@@ -867,6 +897,9 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
                 switch (i) {
                 case HIBERNATION_SHUTDOWN:
                 case HIBERNATION_REBOOT:
+#ifdef CONFIG_SUSPEND
+                case HIBERNATION_SUSPEND:
+#endif
                         break;
                 case HIBERNATION_PLATFORM:
                         if (hibernation_ops)
@@ -907,6 +940,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
                 switch (mode) {
                 case HIBERNATION_SHUTDOWN:
                 case HIBERNATION_REBOOT:
+#ifdef CONFIG_SUSPEND
+                case HIBERNATION_SUSPEND:
+#endif
                         hibernation_mode = mode;
                         break;
                 case HIBERNATION_PLATFORM: