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, 28 insertions, 0 deletions

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 11e22c068e8b..83d505142b00 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -1472,6 +1472,34 @@ void swsusp_close(fmode_t mode)
 	blkdev_put(hib_resume_bdev, mode);
 }
 
+/**
+ *      swsusp_unmark - Unmark swsusp signature in the resume device
+ */
+
+#ifdef CONFIG_SUSPEND
+int swsusp_unmark(void)
+{
+	int error;
+
+	hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
+	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
+		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
+		error = hib_bio_write_page(swsusp_resume_block,
+					swsusp_header, NULL);
+	} else {
+		printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
+		error = -ENODEV;
+	}
+
+	/*
+	 * We just returned from suspend, we don't need the image any more.
+	 */
+	free_all_swap_pages(root_swap);
+
+	return error;
+}
+#endif
+
 static int swsusp_header_init(void)
 {
 	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);