| Message ID | 20180525094648.15464-2-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Fri, May 25, 2018 at 11:46 AM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > From: Thomas Gleixner <tglx@linutronix.de> > > 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(). > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > [bigeasy: cover s2idle] > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > include/linux/kernel.h | 1 + > kernel/power/hibernate.c | 7 +++++++ > kernel/power/suspend.c | 6 ++++++ > 3 files changed, 14 insertions(+) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 6a1eb0b0aad9..7aed92624531 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -542,6 +542,7 @@ extern enum system_states { > SYSTEM_HALT, > SYSTEM_POWER_OFF, > SYSTEM_RESTART, > + SYSTEM_SUSPEND, > } system_state; > > /* This cannot be an enum because some may be used in assembly source. */ > 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..9108a99878bf 100644 > --- a/kernel/power/suspend.c > +++ b/kernel/power/suspend.c > @@ -110,6 +110,7 @@ static void s2idle_loop(void) > { > pm_pr_dbg("suspend-to-idle\n"); > > + system_state = SYSTEM_SUSPEND; And here's the ambiguity. For the other sleep variants SYSTEM_SUSPEND means "all devices have been suspended, interrupts are off and there's one CPU active". Here, device suspend has not even completed entirely. I guess you could set system_state to SYSTEM_SUSPEND right before calling timekeeping_suspend() in tick_freeze() and then back to SYSTEM_RUNNING after timekeeping_resume() has returned in tick_unfreeze(), but talk to Thomas about that first. :-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 6a1eb0b0aad9..7aed92624531 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -542,6 +542,7 @@ extern enum system_states { SYSTEM_HALT, SYSTEM_POWER_OFF, SYSTEM_RESTART, + SYSTEM_SUSPEND, } system_state; /* This cannot be an enum because some may be used in assembly source. */ 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..9108a99878bf 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -110,6 +110,7 @@ static void s2idle_loop(void) { pm_pr_dbg("suspend-to-idle\n"); + system_state = SYSTEM_SUSPEND; for (;;) { int error; @@ -148,6 +149,7 @@ static void s2idle_loop(void) pm_wakeup_clear(false); } + system_state = SYSTEM_RUNNING; pm_pr_dbg("resume from suspend-to-idle\n"); } @@ -428,6 +430,8 @@ 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 +447,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) syscore_resume(); } + system_state = SYSTEM_RUNNING; + arch_suspend_enable_irqs(); BUG_ON(irqs_disabled());