Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Fix PM QOS's user mode interface to work with ASCII input
  PM / Hibernate: Update kerneldoc comments in hibernate.c
  PM / Hibernate: Remove arch_prepare_suspend()
  PM / Hibernate: Update some comments in core hibernate code

arch/frv/include/asm/suspend.h

-/* suspend.h: suspension stuff
- *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#ifndef _ASM_SUSPEND_H
-#define _ASM_SUSPEND_H
-
-static inline int arch_prepare_suspend(void)
-{
-	return 0;
-}
-
-#endif /* _ASM_SUSPEND_H */

arch/mips/include/asm/suspend.h

 #ifndef __ASM_SUSPEND_H
 #define __ASM_SUSPEND_H
 
-static inline int arch_prepare_suspend(void) { return 0; }
-
 /* References to section boundaries */
 extern const void __nosave_begin, __nosave_end;
 

arch/powerpc/include/asm/suspend.h

-#ifndef __ASM_POWERPC_SUSPEND_H
-#define __ASM_POWERPC_SUSPEND_H
-
-static inline int arch_prepare_suspend(void) { return 0; }
-
-#endif /* __ASM_POWERPC_SUSPEND_H */

arch/powerpc/kernel/swsusp.c

@@ -10,7 +10,6 @@
  */
 
 #include <linux/sched.h>
-#include <asm/suspend.h>
 #include <asm/system.h>
 #include <asm/current.h>
 #include <asm/mmu_context.h>

arch/s390/include/asm/suspend.h

-#ifndef __ASM_S390_SUSPEND_H
-#define __ASM_S390_SUSPEND_H
-
-static inline int arch_prepare_suspend(void)
-{
-	return 0;
-}
-
-#endif
-

arch/sh/include/asm/suspend.h

@@ -3,7 +3,6 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/notifier.h>
-static inline int arch_prepare_suspend(void) { return 0; }
 
 #include <asm/ptrace.h>
 

arch/unicore32/include/asm/suspend.h

@@ -14,7 +14,6 @@
 #define __UNICORE_SUSPEND_H__
 
 #ifndef __ASSEMBLY__
-static inline int arch_prepare_suspend(void) { return 0; }
 
 #include <asm/ptrace.h>
 

arch/x86/include/asm/suspend_32.h

@@ -9,8 +9,6 @@
 #include <asm/desc.h>
 #include <asm/i387.h>
 
-static inline int arch_prepare_suspend(void) { return 0; }
-
 /* image of the saved processor state */
 struct saved_context {
 	u16 es, fs, gs, ss;

arch/x86/include/asm/suspend_64.h

@@ -9,11 +9,6 @@
 #include <asm/desc.h>
 #include <asm/i387.h>
 
-static inline int arch_prepare_suspend(void)
-{
-	return 0;
-}
-
 /*
  * Image of the saved processor state, used by the low level ACPI suspend to
  * RAM code and by the low level hibernation code.

kernel/pm_qos_params.c

@@ -40,6 +40,7 @@
 #include <linux/string.h>
 #include <linux/platform_device.h>
 #include <linux/init.h>
+#include <linux/kernel.h>
 
 #include <linux/uaccess.h>
 
@@ -404,24 +405,36 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
 		size_t count, loff_t *f_pos)
 {
 	s32 value;
-	int x;
-	char ascii_value[11];
 	struct pm_qos_request_list *pm_qos_req;
 
 	if (count == sizeof(s32)) {
 		if (copy_from_user(&value, buf, sizeof(s32)))
 			return -EFAULT;
-	} else if (count == 11) { /* len('0x12345678/0') */
-		if (copy_from_user(ascii_value, buf, 11))
+	} else if (count <= 11) { /* ASCII perhaps? */
+		char ascii_value[11];
+		unsigned long int ulval;
+		int ret;
+
+		if (copy_from_user(ascii_value, buf, count))
 			return -EFAULT;
-		if (strlen(ascii_value) != 10)
-			return -EINVAL;
-		x = sscanf(ascii_value, "%x", &value);
-		if (x != 1)
+
+		if (count > 10) {
+			if (ascii_value[10] == '\n')
+				ascii_value[10] = '\0';
+			else
+				return -EINVAL;
+		} else {
+			ascii_value[count] = '\0';
+		}
+		ret = strict_strtoul(ascii_value, 16, &ulval);
+		if (ret) {
+			pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
 			return -EINVAL;
-		pr_debug("%s, %d, 0x%x\n", ascii_value, x, value);
-	} else
+		}
+		value = (s32)lower_32_bits(ulval);
+	} else {
 		return -EINVAL;
+	}
 
 	pm_qos_req = filp->private_data;
 	pm_qos_update_request(pm_qos_req, value);

kernel/power/hibernate.c

@@ -25,7 +25,6 @@
 #include <linux/gfp.h>
 #include <linux/syscore_ops.h>
 #include <scsi/scsi_scan.h>
-#include <asm/suspend.h>
 
 #include "power.h"
 
@@ -55,10 +54,9 @@ static int hibernation_mode = HIBERNATION_SHUTDOWN;
 static const struct platform_hibernation_ops *hibernation_ops;
 
 /**
- * hibernation_set_ops - set the global hibernate operations
- * @ops: the hibernation operations to use in subsequent hibernation transitions
+ * hibernation_set_ops - Set the global hibernate operations.
+ * @ops: Hibernation operations to use in subsequent hibernation transitions.
  */
-
 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
 {
 	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
@@ -115,10 +113,9 @@ static int hibernation_test(int level) { return 0; }
 #endif /* !CONFIG_PM_DEBUG */
 
 /**
- *	platform_begin - tell the platform driver that we're starting
- *	hibernation
+ * platform_begin - Call platform to start hibernation.
+ * @platform_mode: Whether or not to use the platform driver.
  */
-
 static int platform_begin(int platform_mode)
 {
 	return (platform_mode && hibernation_ops) ?
@@ -126,10 +123,9 @@ static int platform_begin(int platform_mode)
 }
 
 /**
- *	platform_end - tell the platform driver that we've entered the
- *	working state
+ * platform_end - Call platform to finish transition to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
  */
-
 static void platform_end(int platform_mode)
 {
 	if (platform_mode && hibernation_ops)
@@ -137,8 +133,11 @@ static void platform_end(int platform_mode)
 }
 
 /**
- *	platform_pre_snapshot - prepare the machine for hibernation using the
- *	platform driver if so configured and return an error code if it fails
+ * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to prepare the system for creating a hibernate image,
+ * if so configured, and return an error code if that fails.
  */
 
 static int platform_pre_snapshot(int platform_mode)
@@ -148,10 +147,14 @@ static int platform_pre_snapshot(int platform_mode)
 }
 
 /**
- *	platform_leave - prepare the machine for switching to the normal mode
- *	of operation using the platform driver (called with interrupts disabled)
+ * platform_leave - Call platform to prepare a transition to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver prepare to prepare the machine for switching to the
+ * normal mode of operation.
+ *
+ * This routine is called on one CPU with interrupts disabled.
  */
-
 static void platform_leave(int platform_mode)
 {
 	if (platform_mode && hibernation_ops)
@@ -159,10 +162,14 @@ static void platform_leave(int platform_mode)
 }
 
 /**
- *	platform_finish - switch the machine to the normal mode of operation
- *	using the platform driver (must be called after platform_prepare())
+ * platform_finish - Call platform to switch the system to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to switch the machine to the normal mode of
+ * operation.
+ *
+ * This routine must be called after platform_prepare().
  */
-
 static void platform_finish(int platform_mode)
 {
 	if (platform_mode && hibernation_ops)
@@ -170,11 +177,15 @@ static void platform_finish(int platform_mode)
 }
 
 /**
- *	platform_pre_restore - prepare the platform for the restoration from a
- *	hibernation image.  If the restore fails after this function has been
- *	called, platform_restore_cleanup() must be called.
+ * platform_pre_restore - Prepare for hibernate image restoration.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to prepare the system for resume from a hibernation
+ * image.
+ *
+ * If the restore fails after this function has been called,
+ * platform_restore_cleanup() must be called.
  */
-
 static int platform_pre_restore(int platform_mode)
 {
 	return (platform_mode && hibernation_ops) ?
@@ -182,12 +193,16 @@ static int platform_pre_restore(int platform_mode)
 }
 
 /**
- *	platform_restore_cleanup - switch the platform to the normal mode of
- *	operation after a failing restore.  If platform_pre_restore() has been
- *	called before the failing restore, this function must be called too,
- *	regardless of the result of platform_pre_restore().
+ * platform_restore_cleanup - Switch to the working state after failing restore.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to switch the system to the normal mode of operation
+ * after a failing restore.
+ *
+ * If platform_pre_restore() has been called before the failing restore, this
+ * function must be called too, regardless of the result of
+ * platform_pre_restore().
  */
-
 static void platform_restore_cleanup(int platform_mode)
 {
 	if (platform_mode && hibernation_ops)
@@ -195,10 +210,9 @@ static void platform_restore_cleanup(int platform_mode)
 }
 
 /**
- *	platform_recover - recover the platform from a failure to suspend
- *	devices.
+ * platform_recover - Recover from a failure to suspend devices.
+ * @platform_mode: Whether or not to use the platform driver.
  */
-
 static void platform_recover(int platform_mode)
 {
 	if (platform_mode && hibernation_ops && hibernation_ops->recover)
@@ -206,13 +220,12 @@ static void platform_recover(int platform_mode)
 }
 
 /**
- *	swsusp_show_speed - print the time elapsed between two events.
- *	@start: Starting event.
- *	@stop: Final event.
- *	@nr_pages -	number of pages processed between @start and @stop
- *	@msg -		introductory message to print
+ * swsusp_show_speed - Print time elapsed between two events during hibernation.
+ * @start: Starting event.
+ * @stop: Final event.
+ * @nr_pages: Number of memory pages processed between @start and @stop.
+ * @msg: Additional diagnostic message to print.
  */
-
 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
 			unsigned nr_pages, char *msg)
 {
@@ -235,25 +248,18 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop,
 }
 
 /**
- *	create_image - freeze devices that need to be frozen with interrupts
- *	off, create the hibernation image and thaw those devices.  Control
- *	reappears in this routine after a restore.
+ * create_image - Create a hibernation image.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
+ * and execute the drivers' .thaw_noirq() callbacks.
+ *
+ * Control reappears in this routine after the subsequent restore.
  */
-
 static int create_image(int platform_mode)
 {
 	int error;
 
-	error = arch_prepare_suspend();
-	if (error)
-		return error;
-
-	/* At this point, dpm_suspend_start() has been called, but *not*
-	 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
-	 * Otherwise, drivers for some devices (e.g. interrupt controllers)
-	 * become desynchronized with the actual state of the hardware
-	 * at resume time, and evil weirdness ensues.
-	 */
 	error = dpm_suspend_noirq(PMSG_FREEZE);
 	if (error) {
 		printk(KERN_ERR "PM: Some devices failed to power down, "
@@ -297,9 +303,6 @@ static int create_image(int platform_mode)
 
  Power_up:
 	syscore_resume();
-	/* NOTE:  dpm_resume_noirq() is just a resume() for devices
-	 * that suspended with irqs off ... no overall powerup.
-	 */
 
  Enable_irqs:
 	local_irq_enable();
@@ -317,14 +320,11 @@ static int create_image(int platform_mode)
 }
 
 /**
- *	hibernation_snapshot - quiesce devices and create the hibernation
- *	snapshot image.
- *	@platform_mode - if set, use the platform driver, if available, to
- *			 prepare the platform firmware for the power transition.
+ * hibernation_snapshot - Quiesce devices and create a hibernation image.
+ * @platform_mode: If set, use platform driver to prepare for the transition.
  *
- *	Must be called with pm_mutex held
+ * This routine must be called with pm_mutex held.
  */
-
 int hibernation_snapshot(int platform_mode)
 {
 	pm_message_t msg = PMSG_RECOVER;
@@ -384,13 +384,14 @@ int hibernation_snapshot(int platform_mode)
 }
 
 /**
- *	resume_target_kernel - prepare devices that need to be suspended with
- *	interrupts off, restore the contents of highmem that have not been
- *	restored yet from the image and run the low level code that will restore
- *	the remaining contents of memory and switch to the just restored target
- *	kernel.
+ * resume_target_kernel - Restore system state from a hibernation image.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
+ * highmem that have not been restored yet from the image and run the low-level
+ * code that will restore the remaining contents of memory and switch to the
+ * just restored target kernel.
  */
-
 static int resume_target_kernel(bool platform_mode)
 {
 	int error;
@@ -416,24 +417,26 @@ static int resume_target_kernel(bool platform_mode)
 	if (error)
 		goto Enable_irqs;
 
-	/* We'll ignore saved state, but this gets preempt count (etc) right */
 	save_processor_state();
 	error = restore_highmem();
 	if (!error) {
 		error = swsusp_arch_resume();
 		/*
 		 * The code below is only ever reached in case of a failure.
-		 * Otherwise execution continues at place where
-		 * swsusp_arch_suspend() was called
+		 * Otherwise, execution continues at the place where
+		 * swsusp_arch_suspend() was called.
 		 */
 		BUG_ON(!error);
-		/* This call to restore_highmem() undos the previous one */
+		/*
+		 * This call to restore_highmem() reverts the changes made by
+		 * the previous one.
+		 */
 		restore_highmem();
 	}
 	/*
 	 * The only reason why swsusp_arch_resume() can fail is memory being
 	 * very tight, so we have to free it as soon as we can to avoid
-	 * subsequent failures
+	 * subsequent failures.
 	 */
 	swsusp_free();
 	restore_processor_state();
@@ -456,14 +459,12 @@ static int resume_target_kernel(bool platform_mode)
 }
 
 /**
- *	hibernation_restore - quiesce devices and restore the hibernation
- *	snapshot image.  If successful, control returns in hibernation_snaphot()
- *	@platform_mode - if set, use the platform driver, if available, to
- *			 prepare the platform firmware for the transition.
+ * hibernation_restore - Quiesce devices and restore from a hibernation image.
+ * @platform_mode: If set, use platform driver to prepare for the transition.
  *
- *	Must be called with pm_mutex held
+ * This routine must be called with pm_mutex held.  If it is successful, control
+ * reappears in the restored target kernel in hibernation_snaphot().
  */
-
 int hibernation_restore(int platform_mode)
 {
 	int error;
@@ -483,10 +484,8 @@ int hibernation_restore(int platform_mode)
 }
 
 /**
- *	hibernation_platform_enter - enter the hibernation state using the
- *	platform driver (if available)
+ * hibernation_platform_enter - Power off the system using the platform driver.
  */
-
 int hibernation_platform_enter(void)
 {
 	int error;
@@ -557,12 +556,12 @@ int hibernation_platform_enter(void)
 }
 
 /**
- *	power_down - Shut the machine down for hibernation.
+ * power_down - Shut the machine down for hibernation.
  *
- *	Use the platform driver, if configured so; otherwise try
- *	to power off or reboot.
+ * Use the platform driver, if configured, to put the system into the sleep
+ * state corresponding to hibernation, or try to power it off or reboot,
+ * depending on the value of hibernation_mode.
  */
-
 static void power_down(void)
 {
 	switch (hibernation_mode) {
@@ -599,9 +598,8 @@ static int prepare_processes(void)
 }
 
 /**
- *	hibernate - The granpappy of the built-in hibernation management
+ * hibernate - Carry out system hibernation, including saving the image.
  */
-
 int hibernate(void)
 {
 	int error;
@@ -679,17 +677,20 @@ int hibernate(void)
 
 
 /**
- *	software_resume - Resume from a saved image.
+ * software_resume - Resume from a saved hibernation image.
  *
- *	Called as a late_initcall (so all devices are discovered and
- *	initialized), we call swsusp to see if we have a saved image or not.
- *	If so, we quiesce devices, the restore the saved image. We will
- *	return above (in hibernate() ) if everything goes well.
- *	Otherwise, we fail gracefully and return to the normally
- *	scheduled program.
+ * This routine is called as a late initcall, when all devices have been
+ * discovered and initialized already.
  *
+ * The image reading code is called to see if there is a hibernation image
+ * available for reading.  If that is the case, devices are quiesced and the
+ * contents of memory is restored from the saved image.
+ *
+ * If this is successful, control reappears in the restored target kernel in
+ * hibernation_snaphot() which returns to hibernate().  Otherwise, the routine
+ * attempts to recover gracefully and make the kernel return to the normal mode
+ * of operation.
  */
-
 static int software_resume(void)
 {
 	int error;
@@ -819,21 +820,17 @@ static const char * const hibernation_modes[] = {
 	[HIBERNATION_TESTPROC]	= "testproc",
 };
 
-/**
- *	disk - Control hibernation mode
- *
- *	Suspend-to-disk can be handled in several ways. We have a few options
- *	for putting the system to sleep - using the platform driver (e.g. ACPI
- *	or other hibernation_ops), powering off the system or rebooting the
- *	system (for testing) as well as the two test modes.
+/*
+ * /sys/power/disk - Control hibernation mode.
  *
- *	The system can support 'platform', and that is known a priori (and
- *	encoded by the presence of hibernation_ops). However, the user may
- *	choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
- *	test modes, 'test' or 'testproc'.
+ * Hibernation can be handled in several ways.  There are a few different ways
+ * to put the system into the sleep state: using the platform driver (e.g. ACPI
+ * or other hibernation_ops), powering it off or rebooting it (for testing
+ * mostly), or using one of the two available test modes.
  *
- *	show() will display what the mode is currently set to.
- *	store() will accept one of
+ * The sysfs file /sys/power/disk provides an interface for selecting the
+ * hibernation mode to use.  Reading from this file causes the available modes
+ * to be printed.  There are 5 modes that can be supported:
  *
  *	'platform'
  *	'shutdown'
@@ -841,8 +838,14 @@ static const char * const hibernation_modes[] = {
  *	'test'
  *	'testproc'
  *
- *	It will only change to 'platform' if the system
- *	supports it (as determined by having hibernation_ops).
+ * If a platform hibernation driver is in use, 'platform' will be supported
+ * and will be used by default.  Otherwise, 'shutdown' will be used by default.
+ * The selected option (i.e. the one corresponding to the current value of
+ * hibernation_mode) is enclosed by a square bracket.
+ *
+ * To select a given hibernation mode it is necessary to write the mode's
+ * string representation (as returned by reading from /sys/power/disk) back
+ * into /sys/power/disk.
  */
 
 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
@@ -875,7 +878,6 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 	return buf-start;
 }
 
-
 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 			  const char *buf, size_t n)
 {