diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2018-05-25 17:54:41 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-05-27 11:55:02 +0200 |
| commit | c1a957d17086d20d52d7f9c8dffaeac2ee09d6f9 (patch) | |
| tree | 55fd308201993a3caf2b2df2bf23ab9ef2ed5718 /kernel/power/suspend.c | |
| parent | 771c577c23bac90597c685971d7297ea00f99d11 (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/suspend.c')
| -rw-r--r-- | kernel/power/suspend.c | 4 |
1 files changed, 4 insertions, 0 deletions
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()); |