diff options
Diffstat (limited to 'kernel/power/suspend.c')
| -rw-r--r-- | kernel/power/suspend.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 09f8397bae15..6fae1e0a331c 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -91,6 +91,16 @@ static void s2idle_enter(void) { trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true); + /* + * The correctness of the code below depends on the number of online + * CPUs being stable, but CPUs cannot be taken offline or put online + * while it is running. + * + * The s2idle_lock must be acquired before the pending wakeup check to + * prevent pm_system_wakeup() from running as a whole between that check + * and the subsequent s2idle_state update in which case a wakeup event + * would get lost. + */ raw_spin_lock_irq(&s2idle_lock); if (pm_wakeup_pending()) goto out; @@ -98,8 +108,6 @@ static void s2idle_enter(void) s2idle_state = S2IDLE_STATE_ENTER; raw_spin_unlock_irq(&s2idle_lock); - cpus_read_lock(); - /* Push all the CPUs into the idle loop. */ wake_up_all_idle_cpus(); /* Make the current CPU wait so it can enter the idle loop too. */ @@ -112,8 +120,6 @@ static void s2idle_enter(void) */ wake_up_all_idle_cpus(); - cpus_read_unlock(); - raw_spin_lock_irq(&s2idle_lock); out: |