Apologies for the confusion. Please add the Cc: stable tag for this patch as this regression affects older kernels too. Link to the patch : http://permalink.gmane.org/gmane.linux.power-management.general/27614 Thanks ! Deepthi On 06/15/2012 05:46 PM, Deepthi Dharwar wrote: > 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 >> > >
