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authorThomas Gleixner <tglx@linutronix.de>2018-05-25 17:54:41 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-05-27 11:55:02 +0200
commitc1a957d17086d20d52d7f9c8dffaeac2ee09d6f9 (patch)
tree55fd308201993a3caf2b2df2bf23ab9ef2ed5718 /kernel/power
parent771c577c23bac90597c685971d7297ea00f99d11 (diff)
PM / suspend: Prevent might sleep splats
timekeeping suspend/resume calls read_persistent_clock() which takes rtc_lock. That results in might sleep warnings because at that point we run with interrupts disabled. We cannot convert rtc_lock to a raw spinlock as that would trigger other might sleep warnings. As a workaround we disable the might sleep warnings by setting system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock contention because hibernate / suspend to RAM is single-CPU at this point. In s2idle's case the system_state is set to SYSTEM_SUSPEND before timekeeping_suspend() which is invoked by the last CPU. In the resume case it set back to SYSTEM_RUNNING after timekeeping_resume() which is invoked by the first CPU in the resume case. The other CPUs will block on tick_freeze_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bigeasy: cover s2idle in tick_freeze() / tick_unfreeze()] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c7
-rw-r--r--kernel/power/suspend.c4
2 files changed, 11 insertions, 0 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 5454cc639a8d..9c85c7822383 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -287,6 +287,8 @@ static int create_image(int platform_mode)
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (error) {
pr_err("Some system devices failed to power down, aborting hibernation\n");
@@ -317,6 +319,7 @@ static int create_image(int platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -445,6 +448,7 @@ static int resume_target_kernel(bool platform_mode)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error)
@@ -478,6 +482,7 @@ static int resume_target_kernel(bool platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -563,6 +568,7 @@ int hibernation_platform_enter(void)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
@@ -575,6 +581,7 @@ int hibernation_platform_enter(void)
Power_up:
syscore_resume();
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4c10be0f4843..5149c77506b3 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
@@ -443,6 +445,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
syscore_resume();
}
+ system_state = SYSTEM_RUNNING;
+
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());