133 lines
3.7 KiB
Diff
133 lines
3.7 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 15 Jul 2010 10:29:00 +0200
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Subject: [PATCH 1/4] PM / suspend: Prevent might sleep splats
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timekeeping suspend/resume calls read_persistent_clock() which takes
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rtc_lock. That results in might sleep warnings because at that point
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we run with interrupts disabled.
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We cannot convert rtc_lock to a raw spinlock as that would trigger
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other might sleep warnings.
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As a workaround we disable the might sleep warnings by setting
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system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
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restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock
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contention because hibernate / suspend to RAM is single-CPU at this
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point.
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In s2idle's case the system_state is set to SYSTEM_SUSPEND before
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timekeeping_suspend() which is invoked by the last CPU. In the resume
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case it set back to SYSTEM_RUNNING after timekeeping_resume() which is
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invoked by the first CPU in the resume case. The other CPUs will block
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on tick_freeze_lock.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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[bigeasy: cover s2idle]
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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include/linux/kernel.h | 1 +
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kernel/power/hibernate.c | 7 +++++++
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kernel/power/suspend.c | 4 ++++
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kernel/time/tick-common.c | 2 ++
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4 files changed, 14 insertions(+)
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--- a/include/linux/kernel.h
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+++ b/include/linux/kernel.h
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@@ -532,6 +532,7 @@ extern enum system_states {
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SYSTEM_HALT,
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SYSTEM_POWER_OFF,
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SYSTEM_RESTART,
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+ SYSTEM_SUSPEND,
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} system_state;
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#define TAINT_PROPRIETARY_MODULE 0
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--- a/kernel/power/hibernate.c
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+++ b/kernel/power/hibernate.c
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@@ -287,6 +287,8 @@ static int create_image(int platform_mod
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local_irq_disable();
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+ system_state = SYSTEM_SUSPEND;
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+
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error = syscore_suspend();
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if (error) {
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pr_err("Some system devices failed to power down, aborting hibernation\n");
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@@ -317,6 +319,7 @@ static int create_image(int platform_mod
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syscore_resume();
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Enable_irqs:
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+ system_state = SYSTEM_RUNNING;
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local_irq_enable();
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Enable_cpus:
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@@ -445,6 +448,7 @@ static int resume_target_kernel(bool pla
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goto Enable_cpus;
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local_irq_disable();
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+ system_state = SYSTEM_SUSPEND;
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error = syscore_suspend();
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if (error)
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@@ -478,6 +482,7 @@ static int resume_target_kernel(bool pla
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syscore_resume();
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Enable_irqs:
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+ system_state = SYSTEM_RUNNING;
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local_irq_enable();
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Enable_cpus:
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@@ -563,6 +568,7 @@ int hibernation_platform_enter(void)
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goto Enable_cpus;
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local_irq_disable();
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+ system_state = SYSTEM_SUSPEND;
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syscore_suspend();
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if (pm_wakeup_pending()) {
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error = -EAGAIN;
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@@ -575,6 +581,7 @@ int hibernation_platform_enter(void)
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Power_up:
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syscore_resume();
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+ system_state = SYSTEM_RUNNING;
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local_irq_enable();
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Enable_cpus:
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--- a/kernel/power/suspend.c
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+++ b/kernel/power/suspend.c
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@@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t
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arch_suspend_disable_irqs();
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BUG_ON(!irqs_disabled());
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+ system_state = SYSTEM_SUSPEND;
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+
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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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@@ -443,6 +445,8 @@ static int suspend_enter(suspend_state_t
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syscore_resume();
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}
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+ system_state = SYSTEM_RUNNING;
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+
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arch_suspend_enable_irqs();
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BUG_ON(irqs_disabled());
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--- a/kernel/time/tick-common.c
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+++ b/kernel/time/tick-common.c
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@@ -490,6 +490,7 @@ void tick_freeze(void)
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if (tick_freeze_depth == num_online_cpus()) {
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trace_suspend_resume(TPS("timekeeping_freeze"),
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smp_processor_id(), true);
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+ system_state = SYSTEM_SUSPEND;
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timekeeping_suspend();
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} else {
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tick_suspend_local();
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@@ -513,6 +514,7 @@ void tick_unfreeze(void)
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if (tick_freeze_depth == num_online_cpus()) {
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timekeeping_resume();
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+ system_state = SYSTEM_RUNNING;
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trace_suspend_resume(TPS("timekeeping_freeze"),
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smp_processor_id(), false);
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} else {
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