Please include this in -stable tree, as this is a regression fix which affects older kernels ( 3.1 onwards ) Link to the patch : http://permalink.gmane.org/gmane.linux.power-management.general/27614 Thanks ! Deepthi On 06/14/2012 01:31 AM, Rafael J. Wysocki wrote: > 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> > > Acked-by: Rafael J. Wysocki <rjw@xxxxxxx> > >> --- >> 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 >> >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
