![Ruchi Kandoi](/assets/img/avatar_default.png)
If a wakeup source is found to be pending in the last stage of suspend after syscore suspend, then the machine won't suspend, but suspend_enter() will return 0. That is confusing, as wakeup detection elsewhere causes -EBUSY to be returned from suspend_enter(). To avoid the confusion, make suspend_enter() return -EBUSY in that case too. Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com> [ rjw: Subject and changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
539 lines
13 KiB
C
539 lines
13 KiB
C
/*
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* kernel/power/suspend.c - Suspend to RAM and standby functionality.
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*
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* Copyright (c) 2003 Patrick Mochel
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* Copyright (c) 2003 Open Source Development Lab
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* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/string.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/cpu.h>
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#include <linux/cpuidle.h>
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#include <linux/syscalls.h>
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#include <linux/gfp.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/suspend.h>
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#include <linux/syscore_ops.h>
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#include <linux/ftrace.h>
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#include <trace/events/power.h>
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#include <linux/compiler.h>
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#include <linux/moduleparam.h>
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#include "power.h"
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const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
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const char *pm_states[PM_SUSPEND_MAX];
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static const struct platform_suspend_ops *suspend_ops;
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static const struct platform_freeze_ops *freeze_ops;
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static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
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enum freeze_state __read_mostly suspend_freeze_state;
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static DEFINE_SPINLOCK(suspend_freeze_lock);
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void freeze_set_ops(const struct platform_freeze_ops *ops)
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{
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lock_system_sleep();
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freeze_ops = ops;
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unlock_system_sleep();
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}
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static void freeze_begin(void)
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{
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suspend_freeze_state = FREEZE_STATE_NONE;
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}
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static void freeze_enter(void)
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{
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spin_lock_irq(&suspend_freeze_lock);
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if (pm_wakeup_pending())
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goto out;
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suspend_freeze_state = FREEZE_STATE_ENTER;
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spin_unlock_irq(&suspend_freeze_lock);
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get_online_cpus();
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cpuidle_resume();
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/* Push all the CPUs into the idle loop. */
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wake_up_all_idle_cpus();
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pr_debug("PM: suspend-to-idle\n");
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/* Make the current CPU wait so it can enter the idle loop too. */
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wait_event(suspend_freeze_wait_head,
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suspend_freeze_state == FREEZE_STATE_WAKE);
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pr_debug("PM: resume from suspend-to-idle\n");
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cpuidle_pause();
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put_online_cpus();
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spin_lock_irq(&suspend_freeze_lock);
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out:
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suspend_freeze_state = FREEZE_STATE_NONE;
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spin_unlock_irq(&suspend_freeze_lock);
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}
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void freeze_wake(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&suspend_freeze_lock, flags);
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if (suspend_freeze_state > FREEZE_STATE_NONE) {
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suspend_freeze_state = FREEZE_STATE_WAKE;
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wake_up(&suspend_freeze_wait_head);
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}
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spin_unlock_irqrestore(&suspend_freeze_lock, flags);
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}
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EXPORT_SYMBOL_GPL(freeze_wake);
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static bool valid_state(suspend_state_t state)
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{
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/*
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* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
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* support and need to be valid to the low level
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* implementation, no valid callback implies that none are valid.
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*/
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return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
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}
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/*
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* If this is set, the "mem" label always corresponds to the deepest sleep state
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* available, the "standby" label corresponds to the second deepest sleep state
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* available (if any), and the "freeze" label corresponds to the remaining
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* available sleep state (if there is one).
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*/
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static bool relative_states;
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static int __init sleep_states_setup(char *str)
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{
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relative_states = !strncmp(str, "1", 1);
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pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
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return 1;
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}
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__setup("relative_sleep_states=", sleep_states_setup);
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/**
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* suspend_set_ops - Set the global suspend method table.
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* @ops: Suspend operations to use.
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*/
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void suspend_set_ops(const struct platform_suspend_ops *ops)
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{
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suspend_state_t i;
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int j = 0;
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lock_system_sleep();
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suspend_ops = ops;
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for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
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if (valid_state(i)) {
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pm_states[i] = pm_labels[j++];
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} else if (!relative_states) {
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pm_states[i] = NULL;
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j++;
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}
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pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
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unlock_system_sleep();
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}
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EXPORT_SYMBOL_GPL(suspend_set_ops);
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/**
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* suspend_valid_only_mem - Generic memory-only valid callback.
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*
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* Platform drivers that implement mem suspend only and only need to check for
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* that in their .valid() callback can use this instead of rolling their own
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* .valid() callback.
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*/
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int suspend_valid_only_mem(suspend_state_t state)
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{
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return state == PM_SUSPEND_MEM;
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}
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EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
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static bool sleep_state_supported(suspend_state_t state)
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{
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return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
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}
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static int platform_suspend_prepare(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
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suspend_ops->prepare() : 0;
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}
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static int platform_suspend_prepare_late(suspend_state_t state)
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{
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return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
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freeze_ops->prepare() : 0;
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}
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static int platform_suspend_prepare_noirq(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
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suspend_ops->prepare_late() : 0;
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}
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static void platform_resume_noirq(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
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suspend_ops->wake();
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}
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static void platform_resume_early(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
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freeze_ops->restore();
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}
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static void platform_resume_finish(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
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suspend_ops->finish();
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}
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static int platform_suspend_begin(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
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return freeze_ops->begin();
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else if (suspend_ops->begin)
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return suspend_ops->begin(state);
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else
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return 0;
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}
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static void platform_resume_end(suspend_state_t state)
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{
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if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
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freeze_ops->end();
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else if (suspend_ops->end)
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suspend_ops->end();
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}
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static void platform_recover(suspend_state_t state)
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{
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if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
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suspend_ops->recover();
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}
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static bool platform_suspend_again(suspend_state_t state)
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{
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return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
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suspend_ops->suspend_again() : false;
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}
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#ifdef CONFIG_PM_DEBUG
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static unsigned int pm_test_delay = 5;
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module_param(pm_test_delay, uint, 0644);
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MODULE_PARM_DESC(pm_test_delay,
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"Number of seconds to wait before resuming from suspend test");
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#endif
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static int suspend_test(int level)
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{
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#ifdef CONFIG_PM_DEBUG
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if (pm_test_level == level) {
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printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
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pm_test_delay);
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mdelay(pm_test_delay * 1000);
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return 1;
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}
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#endif /* !CONFIG_PM_DEBUG */
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return 0;
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}
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/**
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* suspend_prepare - Prepare for entering system sleep state.
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*
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* Common code run for every system sleep state that can be entered (except for
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* hibernation). Run suspend notifiers, allocate the "suspend" console and
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* freeze processes.
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*/
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static int suspend_prepare(suspend_state_t state)
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{
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int error;
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if (!sleep_state_supported(state))
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return -EPERM;
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pm_prepare_console();
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error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
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if (error)
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goto Finish;
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trace_suspend_resume(TPS("freeze_processes"), 0, true);
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error = suspend_freeze_processes();
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trace_suspend_resume(TPS("freeze_processes"), 0, false);
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if (!error)
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return 0;
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suspend_stats.failed_freeze++;
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dpm_save_failed_step(SUSPEND_FREEZE);
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Finish:
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pm_notifier_call_chain(PM_POST_SUSPEND);
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pm_restore_console();
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return error;
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}
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/* default implementation */
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void __weak arch_suspend_disable_irqs(void)
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{
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local_irq_disable();
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}
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/* default implementation */
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void __weak arch_suspend_enable_irqs(void)
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{
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local_irq_enable();
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}
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/**
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* suspend_enter - Make the system enter the given sleep state.
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* @state: System sleep state to enter.
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* @wakeup: Returns information that the sleep state should not be re-entered.
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*
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* This function should be called after devices have been suspended.
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*/
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static int suspend_enter(suspend_state_t state, bool *wakeup)
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{
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int error;
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error = platform_suspend_prepare(state);
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if (error)
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goto Platform_finish;
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error = dpm_suspend_late(PMSG_SUSPEND);
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if (error) {
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printk(KERN_ERR "PM: late suspend of devices failed\n");
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goto Platform_finish;
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}
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error = platform_suspend_prepare_late(state);
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if (error)
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goto Devices_early_resume;
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error = dpm_suspend_noirq(PMSG_SUSPEND);
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if (error) {
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printk(KERN_ERR "PM: noirq suspend of devices failed\n");
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goto Platform_early_resume;
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}
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error = platform_suspend_prepare_noirq(state);
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if (error)
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goto Platform_wake;
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if (suspend_test(TEST_PLATFORM))
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goto Platform_wake;
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/*
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* PM_SUSPEND_FREEZE equals
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* frozen processes + suspended devices + idle processors.
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* Thus we should invoke freeze_enter() soon after
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* all the devices are suspended.
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*/
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if (state == PM_SUSPEND_FREEZE) {
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trace_suspend_resume(TPS("machine_suspend"), state, true);
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freeze_enter();
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trace_suspend_resume(TPS("machine_suspend"), state, false);
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goto Platform_wake;
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}
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error = disable_nonboot_cpus();
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if (error || suspend_test(TEST_CPUS))
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goto Enable_cpus;
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arch_suspend_disable_irqs();
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BUG_ON(!irqs_disabled());
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error = syscore_suspend();
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if (!error) {
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*wakeup = pm_wakeup_pending();
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if (!(suspend_test(TEST_CORE) || *wakeup)) {
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trace_suspend_resume(TPS("machine_suspend"),
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state, true);
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error = suspend_ops->enter(state);
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trace_suspend_resume(TPS("machine_suspend"),
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state, false);
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events_check_enabled = false;
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} else if (*wakeup) {
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error = -EBUSY;
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}
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syscore_resume();
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}
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arch_suspend_enable_irqs();
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BUG_ON(irqs_disabled());
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Enable_cpus:
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enable_nonboot_cpus();
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Platform_wake:
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platform_resume_noirq(state);
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dpm_resume_noirq(PMSG_RESUME);
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Platform_early_resume:
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platform_resume_early(state);
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Devices_early_resume:
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dpm_resume_early(PMSG_RESUME);
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Platform_finish:
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platform_resume_finish(state);
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return error;
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}
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/**
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* suspend_devices_and_enter - Suspend devices and enter system sleep state.
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* @state: System sleep state to enter.
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*/
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int suspend_devices_and_enter(suspend_state_t state)
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{
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int error;
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bool wakeup = false;
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if (!sleep_state_supported(state))
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return -ENOSYS;
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error = platform_suspend_begin(state);
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if (error)
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goto Close;
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suspend_console();
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suspend_test_start();
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error = dpm_suspend_start(PMSG_SUSPEND);
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if (error) {
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pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
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goto Recover_platform;
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}
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suspend_test_finish("suspend devices");
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if (suspend_test(TEST_DEVICES))
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goto Recover_platform;
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do {
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error = suspend_enter(state, &wakeup);
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} while (!error && !wakeup && platform_suspend_again(state));
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Resume_devices:
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suspend_test_start();
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dpm_resume_end(PMSG_RESUME);
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suspend_test_finish("resume devices");
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trace_suspend_resume(TPS("resume_console"), state, true);
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resume_console();
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trace_suspend_resume(TPS("resume_console"), state, false);
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Close:
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platform_resume_end(state);
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return error;
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Recover_platform:
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platform_recover(state);
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goto Resume_devices;
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}
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/**
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* suspend_finish - Clean up before finishing the suspend sequence.
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*
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* Call platform code to clean up, restart processes, and free the console that
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* we've allocated. This routine is not called for hibernation.
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*/
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static void suspend_finish(void)
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{
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suspend_thaw_processes();
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pm_notifier_call_chain(PM_POST_SUSPEND);
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pm_restore_console();
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}
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/**
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* enter_state - Do common work needed to enter system sleep state.
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* @state: System sleep state to enter.
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*
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* Make sure that no one else is trying to put the system into a sleep state.
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* Fail if that's not the case. Otherwise, prepare for system suspend, make the
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* system enter the given sleep state and clean up after wakeup.
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*/
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static int enter_state(suspend_state_t state)
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{
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int error;
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trace_suspend_resume(TPS("suspend_enter"), state, true);
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if (state == PM_SUSPEND_FREEZE) {
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#ifdef CONFIG_PM_DEBUG
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if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
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pr_warning("PM: Unsupported test mode for suspend to idle,"
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"please choose none/freezer/devices/platform.\n");
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return -EAGAIN;
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}
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#endif
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} else if (!valid_state(state)) {
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return -EINVAL;
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}
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if (!mutex_trylock(&pm_mutex))
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return -EBUSY;
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if (state == PM_SUSPEND_FREEZE)
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freeze_begin();
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trace_suspend_resume(TPS("sync_filesystems"), 0, true);
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printk(KERN_INFO "PM: Syncing filesystems ... ");
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sys_sync();
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printk("done.\n");
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trace_suspend_resume(TPS("sync_filesystems"), 0, false);
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pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
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error = suspend_prepare(state);
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if (error)
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goto Unlock;
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if (suspend_test(TEST_FREEZER))
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goto Finish;
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trace_suspend_resume(TPS("suspend_enter"), state, false);
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pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
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pm_restrict_gfp_mask();
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error = suspend_devices_and_enter(state);
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pm_restore_gfp_mask();
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Finish:
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pr_debug("PM: Finishing wakeup.\n");
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suspend_finish();
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Unlock:
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mutex_unlock(&pm_mutex);
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return error;
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}
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/**
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* pm_suspend - Externally visible function for suspending the system.
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* @state: System sleep state to enter.
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*
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* Check if the value of @state represents one of the supported states,
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* execute enter_state() and update system suspend statistics.
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*/
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int pm_suspend(suspend_state_t state)
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{
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int error;
|
|
|
|
if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
|
|
return -EINVAL;
|
|
|
|
error = enter_state(state);
|
|
if (error) {
|
|
suspend_stats.fail++;
|
|
dpm_save_failed_errno(error);
|
|
} else {
|
|
suspend_stats.success++;
|
|
}
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL(pm_suspend);
|