Commit 62c552cc authored by Bojan Smojver's avatar Bojan Smojver Committed by Rafael J. Wysocki
Browse files

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: default avatarBojan Smojver <bojan@rexursive.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 6887a413

Documentation/power/swsusp.txt

+5 −0
Original line number Diff line number Diff line
@@ -33,6 +33,11 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state 


echo platform > /sys/power/disk; echo disk > /sys/power/state



. If you would like to write hibernation image to swap and then suspend

to RAM (provided your platform supports it), you can try



echo suspend > /sys/power/disk; echo disk > /sys/power/state



. If you have SATA disks, you'll need recent kernels with SATA suspend

support. For suspend and resume to work, make sure your disk drivers

are built into kernel -- not modules. [There's way to make

kernel/power/hibernate.c

+36 −0
Original line number Diff line number Diff line
@@ -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:

kernel/power/power.h

+3 −0
Original line number Diff line number Diff line
@@ -156,6 +156,9 @@ extern void swsusp_free(void); 
extern int swsusp_read(unsigned int *flags_p);

extern int swsusp_write(unsigned int flags);

extern void swsusp_close(fmode_t);

#ifdef CONFIG_SUSPEND

extern int swsusp_unmark(void);

#endif



/* kernel/power/block_io.c */

extern struct block_device *hib_resume_bdev;

kernel/power/swap.c

+28 −0
Original line number Diff line number Diff line
@@ -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);

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