![Rafael J. Wysocki](/assets/img/avatar_default.png)
Revert commit 45226e9
(NMI watchdog: fix for lockup detector breakage
on resume) which breaks resume from system suspend on my SH7372
Mackerel board (by causing a NULL pointer dereference to happen) and
is generally wrong, because it abuses the CPU hotplug functionality
in a shamelessly blatant way.
The original issue should be addressed through appropriate syscore
resume callback instead.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
330 lines
7.4 KiB
C
330 lines
7.4 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/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 "power.h"
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const char *const pm_states[PM_SUSPEND_MAX] = {
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[PM_SUSPEND_STANDBY] = "standby",
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[PM_SUSPEND_MEM] = "mem",
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};
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static const struct platform_suspend_ops *suspend_ops;
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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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lock_system_sleep();
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suspend_ops = ops;
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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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bool valid_state(suspend_state_t state)
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{
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/*
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* All states need lowlevel support and need to be valid to the lowlevel
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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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* 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 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 5 seconds.\n");
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mdelay(5000);
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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(void)
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{
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int error;
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if (!suspend_ops || !suspend_ops->enter)
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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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error = suspend_freeze_processes();
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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 __attribute__ ((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 __attribute__ ((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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if (suspend_ops->prepare) {
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error = suspend_ops->prepare();
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if (error)
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goto Platform_finish;
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}
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error = dpm_suspend_end(PMSG_SUSPEND);
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if (error) {
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printk(KERN_ERR "PM: Some devices failed to power down\n");
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goto Platform_finish;
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}
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if (suspend_ops->prepare_late) {
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error = suspend_ops->prepare_late();
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if (error)
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goto Platform_wake;
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}
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if (suspend_test(TEST_PLATFORM))
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goto Platform_wake;
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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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error = suspend_ops->enter(state);
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events_check_enabled = false;
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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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if (suspend_ops->wake)
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suspend_ops->wake();
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dpm_resume_start(PMSG_RESUME);
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Platform_finish:
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if (suspend_ops->finish)
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suspend_ops->finish();
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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 (!suspend_ops)
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return -ENOSYS;
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trace_machine_suspend(state);
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if (suspend_ops->begin) {
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error = suspend_ops->begin(state);
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if (error)
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goto Close;
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}
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suspend_console();
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ftrace_stop();
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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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printk(KERN_ERR "PM: Some devices failed to suspend\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
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&& suspend_ops->suspend_again && suspend_ops->suspend_again());
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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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ftrace_start();
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resume_console();
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Close:
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if (suspend_ops->end)
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suspend_ops->end();
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trace_machine_suspend(PWR_EVENT_EXIT);
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return error;
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Recover_platform:
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if (suspend_ops->recover)
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suspend_ops->recover();
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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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if (!valid_state(state))
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return -ENODEV;
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if (!mutex_trylock(&pm_mutex))
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return -EBUSY;
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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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pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
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error = suspend_prepare();
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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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pr_debug("PM: Entering %s sleep\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;
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if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
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return -EINVAL;
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error = enter_state(state);
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if (error) {
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suspend_stats.fail++;
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dpm_save_failed_errno(error);
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} else {
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suspend_stats.success++;
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}
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return error;
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}
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EXPORT_SYMBOL(pm_suspend);
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