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Commit 25913052 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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[PATCH] swsusp: Change code ordering in user.c 

Change the ordering of code in kernel/power/user.c so that device_suspend() is
called before disable_nonboot_cpus() and device_resume() is called after
enable_nonboot_cpus().  This is needed to make the userland suspend call
pm_ops->finish() after enable_nonboot_cpus() and before device_resume(), as
indicated by the recent discussion on Linux-PM (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html

).

The changes here only affect the userland interface of swsusp.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ed746e3b

kernel/power/user.c

+58 −34
Original line number Diff line number Diff line
@@ -122,6 +122,59 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, 
	return res;

}



static inline int snapshot_suspend(void)

{

	int error;



	mutex_lock(&pm_mutex);

	/* Free memory before shutting down devices. */

	error = swsusp_shrink_memory();

	if (error)

		goto Finish;



	suspend_console();

	error = device_suspend(PMSG_FREEZE);

	if (error)

		goto Resume_devices;



	error = disable_nonboot_cpus();

	if (!error) {

		in_suspend = 1;

		error = swsusp_suspend();

	}

	enable_nonboot_cpus();

 Resume_devices:

	device_resume();

	resume_console();

 Finish:

	mutex_unlock(&pm_mutex);

	return error;

}



static inline int snapshot_restore(void)

{

	int error;



	mutex_lock(&pm_mutex);

	pm_prepare_console();

	suspend_console();

	error = device_suspend(PMSG_PRETHAW);

	if (error)

		goto Resume_devices;



	error = disable_nonboot_cpus();

	if (!error)

		error = swsusp_resume();



	enable_nonboot_cpus();

 Resume_devices:

	device_resume();

	resume_console();

	pm_restore_console();

	mutex_unlock(&pm_mutex);

	return error;

}



static int snapshot_ioctl(struct inode *inode, struct file *filp,

                          unsigned int cmd, unsigned long arg)

{
@@ -145,15 +198,10 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, 
		if (data->frozen)

			break;

		mutex_lock(&pm_mutex);

		error = disable_nonboot_cpus();

		if (!error) {

			error = freeze_processes();

			if (error) {

		if (freeze_processes()) {

			thaw_processes();

				enable_nonboot_cpus();

			error = -EBUSY;

		}

		}

		mutex_unlock(&pm_mutex);

		if (!error)

			data->frozen = 1;
@@ -164,7 +212,6 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, 
			break;

		mutex_lock(&pm_mutex);

		thaw_processes();

		enable_nonboot_cpus();

		mutex_unlock(&pm_mutex);

		data->frozen = 0;

		break;
@@ -174,20 +221,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, 
			error = -EPERM;

			break;

		}

		mutex_lock(&pm_mutex);

		/* Free memory before shutting down devices. */

		error = swsusp_shrink_memory();

		if (!error) {

			suspend_console();

			error = device_suspend(PMSG_FREEZE);

			if (!error) {

				in_suspend = 1;

				error = swsusp_suspend();

				device_resume();

			}

			resume_console();

		}

		mutex_unlock(&pm_mutex);

		error = snapshot_suspend();

		if (!error)

			error = put_user(in_suspend, (unsigned int __user *)arg);

		if (!error)
@@ -201,17 +235,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, 
			error = -EPERM;

			break;

		}

		mutex_lock(&pm_mutex);

		pm_prepare_console();

		suspend_console();

		error = device_suspend(PMSG_PRETHAW);

		if (!error) {

			error = swsusp_resume();

			device_resume();

		}

		resume_console();

		pm_restore_console();

		mutex_unlock(&pm_mutex);

		error = snapshot_restore();

		break;



	case SNAPSHOT_FREE: