On Wednesday, June 13, 2012, Deepthi Dharwar wrote: > > From: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx> > > Fix suspend/resume regression caused by cpuidle cleanup. > > Commit e978aa7d7d57d04eb5f88a7507c4fb98577def77 ( cpuidle: Move > dev->last_residency update to driver enter routine; remove dev->last_state) > was breaking suspend on laptops, as reported in the below link > - https://lkml.org/lkml/2011/11/11/164 > > This was fixed in commit 3439a8da16bcad6b0982ece938c9f8299bb53584 > (ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression) > by removing acpi_idle_suspend flag. > - https://lkml.org/lkml/2011/11/14/74 > > But this fix did not work on all systems > as Suspend/resume regression was reported on Lenovo S10-3 > recently by Dave. > - https://lkml.org/lkml/2012/5/27/115 > It looked like with commit e978aa7d broke suspend and > with commit 3439a8da resume was not working with acpi_idle driver. > > This patch fixes the regression that caused this issue > in the first place. acpi_idle_suspend flag is essential on > some x86 systems to prevent the cpus from going to deeper C-states > when suspend is triggered ( commit b04e7bdb984 ) > So reverting the commit 3439a8da is essential. > > By default, irqs are disabled in cpu_idle arch specific call > and re-enabled in idle state return path . As the acpi_idle_suspend > flag was being set during suspend, which prevented the cpus > going to deeper idle states, it is essential to > enabling the irqs in its return path too. > > To address the suspend issue, > we were not re-enabling the interrupts while returning from > acpi_idle_enter_bm() routine if acpi_idle_suspend flag is set. > and this was causing suspend failure. > > In addition to the above fix, a sanity check has also been added > in x86 arch specific cpu_idle call to ensure that the idle call > always returns with IRQs enabled. > > This patch applies on 3.5-rc2 > --- > > Reported-and-Tested-by: Dav Hansen <dave@xxxxxxxxxxxxxxxxxx> > Tested-by: Preeti Murthy <preeti@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx> > Reviewed-by: Srivatsa S Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Applied to linux-pm/linux-next, will be pushed to Linus later this week. Thanks, Rafael > --- > arch/x86/kernel/process.c | 6 ++++++ > drivers/acpi/processor_idle.c | 28 ++++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c > index 735279e..8ab76ad 100644 > --- a/arch/x86/kernel/process.c > +++ b/arch/x86/kernel/process.c > @@ -460,6 +460,12 @@ void cpu_idle(void) > pm_idle(); > > rcu_idle_exit(); > + > + /* > + * Sanity check to ensure that idle call returns > + * with IRQs enabled > + */ > + WARN_ON(irqs_disabled()); > start_critical_timings(); > > /* In many cases the interrupt that ended idle > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index f3decb3..c2ffd84 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -224,6 +224,7 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr, > /* > * Suspend / resume control > */ > +static int acpi_idle_suspend; > static u32 saved_bm_rld; > > static void acpi_idle_bm_rld_save(void) > @@ -242,13 +243,21 @@ static void acpi_idle_bm_rld_restore(void) > > int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) > { > + if (acpi_idle_suspend == 1) > + return 0; > + > acpi_idle_bm_rld_save(); > + acpi_idle_suspend = 1; > return 0; > } > > int acpi_processor_resume(struct acpi_device * device) > { > + if (acpi_idle_suspend == 0) > + return 0; > + > acpi_idle_bm_rld_restore(); > + acpi_idle_suspend = 0; > return 0; > } > > @@ -754,6 +763,12 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, > > local_irq_disable(); > > + if (acpi_idle_suspend) { > + local_irq_enable(); > + cpu_relax(); > + return -EINVAL; > + } > + > lapic_timer_state_broadcast(pr, cx, 1); > kt1 = ktime_get_real(); > acpi_idle_do_entry(cx); > @@ -823,6 +838,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, > > local_irq_disable(); > > + if (acpi_idle_suspend) { > + local_irq_enable(); > + cpu_relax(); > + return -EINVAL; > + } > + > if (cx->entry_method != ACPI_CSTATE_FFH) { > current_thread_info()->status &= ~TS_POLLING; > /* > @@ -901,6 +922,13 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, > if (unlikely(!pr)) > return -EINVAL; > > + if (acpi_idle_suspend) { > + if (irqs_disabled()) > + local_irq_enable(); > + cpu_relax(); > + return -EINVAL; > + } > + > if (!cx->bm_sts_skip && acpi_idle_bm_check()) { > if (drv->safe_state_index >= 0) { > return drv->states[drv->safe_state_index].enter(dev, > > Regards, > Deepthi > > >
