| Message ID | 20180524142426.jeyszeqdrjvb3tob@linutronix.de (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On Thu, May 24, 2018 at 4:24 PM, 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> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Hmm. Don't we also need to cover suspend-to-idle? > --- > include/linux/kernel.h | 1 + > kernel/power/hibernate.c | 7 +++++++ > kernel/power/suspend.c | 4 ++++ > 3 files changed, 12 insertions(+) > > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -532,6 +532,7 @@ extern enum system_states { > SYSTEM_HALT, > SYSTEM_POWER_OFF, > SYSTEM_RESTART, > + SYSTEM_SUSPEND, > } system_state; > > #define TAINT_PROPRIETARY_MODULE 0 > --- a/kernel/power/hibernate.c > +++ b/kernel/power/hibernate.c > @@ -287,6 +287,8 @@ static int create_image(int platform_mod > > 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_mod > syscore_resume(); > > Enable_irqs: > + system_state = SYSTEM_RUNNING; > local_irq_enable(); > > Enable_cpus: > @@ -445,6 +448,7 @@ static int resume_target_kernel(bool pla > 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 pla > 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: > --- a/kernel/power/suspend.c > +++ b/kernel/power/suspend.c > @@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t > 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 > syscore_resume(); > } > > + system_state = SYSTEM_RUNNING; > + > arch_suspend_enable_irqs(); > BUG_ON(irqs_disabled()); >
On 2018-05-24 17:07:16 [+0200], Rafael J. Wysocki wrote: > On Thu, May 24, 2018 at 4:24 PM, 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> > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > > Hmm. Don't we also need to cover suspend-to-idle? Well, if you agree with the approach then I would look into it. Sebastian
On Thu, May 24, 2018 at 5:45 PM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > On 2018-05-24 17:07:16 [+0200], Rafael J. Wysocki wrote: >> On Thu, May 24, 2018 at 4:24 PM, 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> >> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> >> >> Hmm. Don't we also need to cover suspend-to-idle? > > Well, if you agree with the approach then I would look into it. As long as the SYSTEM_SUSPEND system state is defined unambiguously, I don't have a problem with doing this.
--- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -532,6 +532,7 @@ extern enum system_states { SYSTEM_HALT, SYSTEM_POWER_OFF, SYSTEM_RESTART, + SYSTEM_SUSPEND, } system_state; #define TAINT_PROPRIETARY_MODULE 0 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -287,6 +287,8 @@ static int create_image(int platform_mod 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_mod syscore_resume(); Enable_irqs: + system_state = SYSTEM_RUNNING; local_irq_enable(); Enable_cpus: @@ -445,6 +448,7 @@ static int resume_target_kernel(bool pla 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 pla 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: --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t 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 syscore_resume(); } + system_state = SYSTEM_RUNNING; + arch_suspend_enable_irqs(); BUG_ON(irqs_disabled());