Re: Suspend/resume regressions on Lenovo S10-3

Re: Suspend/resume regressions on Lenovo S10-3

[Deepthi Dharwar]

On 05/28/2012 07:23 AM, Dave Hansen wrote:

> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
> trouble working with the intel_idle driver, so I usually compile that
> out an use the acpi one.  However, just after 3.1, suspend/resume broke.
>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
> it down to the commits around:
> 
> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> 
> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
> different symptom: it suspends, but hangs on resume from suspend.  I
> think _that_ delta in the behavior was caused by:
> 
> 	3439a8da16bcad6b0982ece938c9f8299bb53584
> 
>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
> 		regression)
> 
> It's a bit of a pain to bisect these two different things in parallel.
> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
> kernels in, I'm not sure that's working very well. :)
> 
> Deepthi, do you have any idea why your patches broke me in the first
> place?  Perhaps we should fix that regression first before we go on and
> try to figure out what changed to let it suspend again, but break later.


Hi Dave,

Sorry about my patches breaking your suspend-resume.

I, basically tried out building and booting 3.1 kernel with 
my patch set to reproduce the failure. I could clearly
see suspend not happening. It turns out to be 
a bug with my first patch in global registration
series submitted earlier.

e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7

The following patch, fixes the suspend issues
seen on my laptop due to earlier cpuidle cleanup 
(Lenevo T420 booting with acpi_idle enabled). 
Can you please give this a try
on top of my patch set (without Rafael's fix) 
and see if it fixes the problem for you. 
I am not reverting acpi_idle_suspend flag and 
hopefully it should resume fine too. 

---

This patch fixes suspend-resume issue seen in the kernel 3.1
series using acpi_idle_driver because of cpuidle global 
registration cleanup.
Here, when acpi_idle_suspend flag was set ( during suspend)
the interrupts were not getting enabled in acpi_idle_enter_bm()
routine which was causing the system to hang.


Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>

---
 drivers/acpi/processor_idle.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 24fe3af..6e35293 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	if (unlikely(!pr))
 		return -EINVAL;
 
-
 	if (acpi_idle_suspend) {
+		local_irq_disable();
+		local_irq_enable();
 		cpu_relax();
 		return -EINVAL;
 	}

Cheers,
Deepthi

Re: Suspend/resume regressions on Lenovo S10-3

[Rafael J. Wysocki]

On Wednesday, June 06, 2012, Deepthi Dharwar wrote:
> On 05/28/2012 07:23 AM, Dave Hansen wrote:
> 
> > I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
> > trouble working with the intel_idle driver, so I usually compile that
> > out an use the acpi one.  However, just after 3.1, suspend/resume broke.
> >  'echo mem > /sys/power/state' would hang before suspending.  I bisected
> > it down to the commits around:
> > 
> > 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> > 
> > by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
> > different symptom: it suspends, but hangs on resume from suspend.  I
> > think _that_ delta in the behavior was caused by:
> > 
> > 	3439a8da16bcad6b0982ece938c9f8299bb53584
> > 
> >         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
> > 		regression)
> > 
> > It's a bit of a pain to bisect these two different things in parallel.
> > I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
> > on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
> > kernels in, I'm not sure that's working very well. :)
> > 
> > Deepthi, do you have any idea why your patches broke me in the first
> > place?  Perhaps we should fix that regression first before we go on and
> > try to figure out what changed to let it suspend again, but break later.
> 
> 
> Hi Dave,
> 
> Sorry about my patches breaking your suspend-resume.
> 
> I, basically tried out building and booting 3.1 kernel with 
> my patch set to reproduce the failure. I could clearly
> see suspend not happening. It turns out to be 
> a bug with my first patch in global registration
> series submitted earlier.
> 
> e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> 
> The following patch, fixes the suspend issues
> seen on my laptop due to earlier cpuidle cleanup 
> (Lenevo T420 booting with acpi_idle enabled). 
> Can you please give this a try
> on top of my patch set (without Rafael's fix) 
> and see if it fixes the problem for you. 
> I am not reverting acpi_idle_suspend flag and 
> hopefully it should resume fine too. 
> 
> ---
> 
> This patch fixes suspend-resume issue seen in the kernel 3.1
> series using acpi_idle_driver because of cpuidle global 
> registration cleanup.
> Here, when acpi_idle_suspend flag was set ( during suspend)
> the interrupts were not getting enabled in acpi_idle_enter_bm()
> routine which was causing the system to hang.
> 
> 
> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
> 
> ---
>  drivers/acpi/processor_idle.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 24fe3af..6e35293 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
>  	if (unlikely(!pr))
>  		return -EINVAL;
>  
> -
>  	if (acpi_idle_suspend) {
> +		local_irq_disable();
> +		local_irq_enable();
>  		cpu_relax();
>  		return -EINVAL;
>  	}

May I say this is ugly?  Why can't we track the status of interrupts
properly here?

Rafael

Re: [linux-pm] Suspend/resume regressions on Lenovo S10-3

[Alan Stern]

On Wed, 6 Jun 2012, Rafael J. Wysocki wrote:

> > --- a/drivers/acpi/processor_idle.c
> > +++ b/drivers/acpi/processor_idle.c
> > @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
> >  	if (unlikely(!pr))
> >  		return -EINVAL;
> >  
> > -
> >  	if (acpi_idle_suspend) {
> > +		local_irq_disable();
> > +		local_irq_enable();
> >  		cpu_relax();
> >  		return -EINVAL;
> >  	}
> 
> May I say this is ugly?  Why can't we track the status of interrupts
> properly here?

It's not just ugly; it's illogical.  What reason could there possibly
be for disabling interrupts and then enabling them again without doing
anything in between?

Alan Stern

Re: Suspend/resume regressions on Lenovo S10-3

[Deepthi Dharwar]

On 06/06/2012 07:13 PM, Rafael J. Wysocki wrote:

> On Wednesday, June 06, 2012, Deepthi Dharwar wrote:
>> On 05/28/2012 07:23 AM, Dave Hansen wrote:
>>
>>> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
>>> trouble working with the intel_idle driver, so I usually compile that
>>> out an use the acpi one.  However, just after 3.1, suspend/resume broke.
>>>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
>>> it down to the commits around:
>>>
>>> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
>>>
>>> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
>>> different symptom: it suspends, but hangs on resume from suspend.  I
>>> think _that_ delta in the behavior was caused by:
>>>
>>> 	3439a8da16bcad6b0982ece938c9f8299bb53584
>>>
>>>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
>>> 		regression)
>>>
>>> It's a bit of a pain to bisect these two different things in parallel.
>>> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
>>> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
>>> kernels in, I'm not sure that's working very well. :)
>>>
>>> Deepthi, do you have any idea why your patches broke me in the first
>>> place?  Perhaps we should fix that regression first before we go on and
>>> try to figure out what changed to let it suspend again, but break later.
>>
>>
>> Hi Dave,
>>
>> Sorry about my patches breaking your suspend-resume.
>>
>> I, basically tried out building and booting 3.1 kernel with 
>> my patch set to reproduce the failure. I could clearly
>> see suspend not happening. It turns out to be 
>> a bug with my first patch in global registration
>> series submitted earlier.
>>
>> e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
>>
>> The following patch, fixes the suspend issues
>> seen on my laptop due to earlier cpuidle cleanup 
>> (Lenevo T420 booting with acpi_idle enabled). 
>> Can you please give this a try
>> on top of my patch set (without Rafael's fix) 
>> and see if it fixes the problem for you. 
>> I am not reverting acpi_idle_suspend flag and 
>> hopefully it should resume fine too. 
>>
>> ---
>>
>> This patch fixes suspend-resume issue seen in the kernel 3.1
>> series using acpi_idle_driver because of cpuidle global 
>> registration cleanup.
>> Here, when acpi_idle_suspend flag was set ( during suspend)
>> the interrupts were not getting enabled in acpi_idle_enter_bm()
>> routine which was causing the system to hang.
>>
>>
>> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
>>
>> ---
>>  drivers/acpi/processor_idle.c |    3 ++-
>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
>> index 24fe3af..6e35293 100644
>> --- a/drivers/acpi/processor_idle.c
>> +++ b/drivers/acpi/processor_idle.c
>> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
>>  	if (unlikely(!pr))
>>  		return -EINVAL;
>>  
>> -
>>  	if (acpi_idle_suspend) {
>> +		local_irq_disable();
>> +		local_irq_enable();
>>  		cpu_relax();
>>  		return -EINVAL;
>>  	}
> 
> May I say this is ugly?  Why can't we track the status of interrupts
> properly here?



I agree. Just the irq_enable call should do the trick.
Once the cpu enters idle via cpu_idle call, irqs are disabled. We
need to enable them if acpi_idle_suspend is set.
Else we'll see a hang during suspend.

The patch that was posted was just for workaround patch.
I shall do some more testing with just irq_enable call
and then shall post the fix which can be considered
for inclusion.

Cheers
Deepthi

Re: Suspend/resume regressions on Lenovo S10-3

[Rafael J. Wysocki]

On Wednesday, June 06, 2012, Deepthi Dharwar wrote:
> On 06/06/2012 07:13 PM, Rafael J. Wysocki wrote:
> 
> > On Wednesday, June 06, 2012, Deepthi Dharwar wrote:
> >> On 05/28/2012 07:23 AM, Dave Hansen wrote:
> >>
> >>> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
> >>> trouble working with the intel_idle driver, so I usually compile that
> >>> out an use the acpi one.  However, just after 3.1, suspend/resume broke.
> >>>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
> >>> it down to the commits around:
> >>>
> >>> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> >>>
> >>> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
> >>> different symptom: it suspends, but hangs on resume from suspend.  I
> >>> think _that_ delta in the behavior was caused by:
> >>>
> >>> 	3439a8da16bcad6b0982ece938c9f8299bb53584
> >>>
> >>>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
> >>> 		regression)
> >>>
> >>> It's a bit of a pain to bisect these two different things in parallel.
> >>> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
> >>> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
> >>> kernels in, I'm not sure that's working very well. :)
> >>>
> >>> Deepthi, do you have any idea why your patches broke me in the first
> >>> place?  Perhaps we should fix that regression first before we go on and
> >>> try to figure out what changed to let it suspend again, but break later.
> >>
> >>
> >> Hi Dave,
> >>
> >> Sorry about my patches breaking your suspend-resume.
> >>
> >> I, basically tried out building and booting 3.1 kernel with 
> >> my patch set to reproduce the failure. I could clearly
> >> see suspend not happening. It turns out to be 
> >> a bug with my first patch in global registration
> >> series submitted earlier.
> >>
> >> e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> >>
> >> The following patch, fixes the suspend issues
> >> seen on my laptop due to earlier cpuidle cleanup 
> >> (Lenevo T420 booting with acpi_idle enabled). 
> >> Can you please give this a try
> >> on top of my patch set (without Rafael's fix) 
> >> and see if it fixes the problem for you. 
> >> I am not reverting acpi_idle_suspend flag and 
> >> hopefully it should resume fine too. 
> >>
> >> ---
> >>
> >> This patch fixes suspend-resume issue seen in the kernel 3.1
> >> series using acpi_idle_driver because of cpuidle global 
> >> registration cleanup.
> >> Here, when acpi_idle_suspend flag was set ( during suspend)
> >> the interrupts were not getting enabled in acpi_idle_enter_bm()
> >> routine which was causing the system to hang.
> >>
> >>
> >> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
> >>
> >> ---
> >>  drivers/acpi/processor_idle.c |    3 ++-
> >>  1 files changed, 2 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> >> index 24fe3af..6e35293 100644
> >> --- a/drivers/acpi/processor_idle.c
> >> +++ b/drivers/acpi/processor_idle.c
> >> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
> >>  	if (unlikely(!pr))
> >>  		return -EINVAL;
> >>  
> >> -
> >>  	if (acpi_idle_suspend) {
> >> +		local_irq_disable();
> >> +		local_irq_enable();
> >>  		cpu_relax();
> >>  		return -EINVAL;
> >>  	}
> > 
> > May I say this is ugly?  Why can't we track the status of interrupts
> > properly here?
> 
> 
> 
> I agree. Just the irq_enable call should do the trick.
> Once the cpu enters idle via cpu_idle call, irqs are disabled. We
> need to enable them if acpi_idle_suspend is set.
> Else we'll see a hang during suspend.
> 
> The patch that was posted was just for workaround patch.
> I shall do some more testing with just irq_enable call
> and then shall post the fix which can be considered
> for inclusion.

I see.  OK, then, looking forward to seeing the final patch. :-)

Thanks,
Rafael

Re: Suspend/resume regressions on Lenovo S10-3

[Srivatsa S. Bhat]

On 06/06/2012 07:13 PM, Rafael J. Wysocki wrote:

> On Wednesday, June 06, 2012, Deepthi Dharwar wrote:
>> On 05/28/2012 07:23 AM, Dave Hansen wrote:
>>
>>> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
>>> trouble working with the intel_idle driver, so I usually compile that
>>> out an use the acpi one.  However, just after 3.1, suspend/resume broke.
>>>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
>>> it down to the commits around:
>>>
>>> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
>>>
>>> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
>>> different symptom: it suspends, but hangs on resume from suspend.  I
>>> think _that_ delta in the behavior was caused by:
>>>
>>> 	3439a8da16bcad6b0982ece938c9f8299bb53584
>>>
>>>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
>>> 		regression)
>>>
>>> It's a bit of a pain to bisect these two different things in parallel.
>>> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
>>> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
>>> kernels in, I'm not sure that's working very well. :)
>>>
>>> Deepthi, do you have any idea why your patches broke me in the first
>>> place?  Perhaps we should fix that regression first before we go on and
>>> try to figure out what changed to let it suspend again, but break later.
>>
>>
>> Hi Dave,
>>
>> Sorry about my patches breaking your suspend-resume.
>>
>> I, basically tried out building and booting 3.1 kernel with 
>> my patch set to reproduce the failure. I could clearly
>> see suspend not happening. It turns out to be 
>> a bug with my first patch in global registration
>> series submitted earlier.
>>
>> e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
>>
>> The following patch, fixes the suspend issues
>> seen on my laptop due to earlier cpuidle cleanup 
>> (Lenevo T420 booting with acpi_idle enabled). 
>> Can you please give this a try
>> on top of my patch set (without Rafael's fix) 
>> and see if it fixes the problem for you. 
>> I am not reverting acpi_idle_suspend flag and 
>> hopefully it should resume fine too. 
>>
>> ---
>>
>> This patch fixes suspend-resume issue seen in the kernel 3.1
>> series using acpi_idle_driver because of cpuidle global 
>> registration cleanup.
>> Here, when acpi_idle_suspend flag was set ( during suspend)
>> the interrupts were not getting enabled in acpi_idle_enter_bm()
>> routine which was causing the system to hang.
>>
>>
>> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
>>
>> ---
>>  drivers/acpi/processor_idle.c |    3 ++-
>>  1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
>> index 24fe3af..6e35293 100644
>> --- a/drivers/acpi/processor_idle.c
>> +++ b/drivers/acpi/processor_idle.c
>> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
>>  	if (unlikely(!pr))
>>  		return -EINVAL;
>>  
>> -
>>  	if (acpi_idle_suspend) {
>> +		local_irq_disable();
>> +		local_irq_enable();
>>  		cpu_relax();
>>  		return -EINVAL;
>>  	}
> 
> May I say this is ugly?  Why can't we track the status of interrupts
> properly here?
> 


Btw, Deepthi, when you are modifying this to keep track of interrupt enabled/
disabled status, I think it would be worthwhile to also add a WARN_ON() in
cpu_idle() inside arch/x86/kernel/process.c, just like how ARM and sh do it.

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 735279e..1ca7e1a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -459,6 +459,9 @@ void cpu_idle(void)
                        if (cpuidle_idle_call())
                                pm_idle();

+                       /* The idle routine must return with IRQs enabled. */
+                       WARN_ON(irqs_disabled());
+
                        rcu_idle_exit();
                        start_critical_timings();

[If we had done this earlier, we could have caught the bug right when the
patch went in :-)]

Regards,

Srivatsa S. Bhat

Re: Suspend/resume regressions on Lenovo S10-3

[Dave Hansen]

On 06/06/2012 05:51 AM, Deepthi Dharwar wrote:
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 24fe3af..6e35293 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
>  	if (unlikely(!pr))
>  		return -EINVAL;
> 
> -
>  	if (acpi_idle_suspend) {
> +		local_irq_disable();
> +		local_irq_enable();
>  		cpu_relax();
>  		return -EINVAL;
>  	}

Heh, that is quite the hack. :)

However, it does at least work around my problem: I can suspend again
with 46bcfad + your patch.

Re: Suspend/resume regressions on Lenovo S10-3

[Srivatsa S. Bhat]

Hi Dave,

On 06/06/2012 06:21 PM, Deepthi Dharwar wrote:

> On 05/28/2012 07:23 AM, Dave Hansen wrote:
> 
>> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
>> trouble working with the intel_idle driver, so I usually compile that
>> out an use the acpi one.


What problem did you face with intel_idle driver? Is it suspend/resume
related?

I see a comment in drivers/idle/intel_idle.c such as:

/*
 * Known limitations
 * [...]
 *
 * ACPI has a .suspend hack to turn off deep c-statees during suspend
 * to avoid complications with the lapic timer workaround.
 * Have not seen issues with suspend, but may need same workaround here.
 *
 */

So, if you are facing suspend issues with the intel_idle driver, we probably
need to add that same workaround here as well, to make it work.

Please let us know what problem you are facing.

Regards,
Srivatsa S. Bhat

>>  However, just after 3.1, suspend/resume broke.
>>  'echo mem > /sys/power/state' would hang before suspending.  I bisected
>> it down to the commits around:
>>
>> 	e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
>>
>> by Deepthi.  But, current mainline (v3.4-07644-g07acfc2) hangs with a
>> different symptom: it suspends, but hangs on resume from suspend.  I
>> think _that_ delta in the behavior was caused by:
>>
>> 	3439a8da16bcad6b0982ece938c9f8299bb53584
>>
>>         ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend
>> 		regression)
>>
>> It's a bit of a pain to bisect these two different things in parallel.
>> I was trying to tell git bisect 'good' on working suspend/resume, 'bad'
>> on the hang during resume, and 'skip' on the hangs _during_ suspend.  83
>> kernels in, I'm not sure that's working very well. :)
>>
>> Deepthi, do you have any idea why your patches broke me in the first
>> place?  Perhaps we should fix that regression first before we go on and
>> try to figure out what changed to let it suspend again, but break later.
> 
> 
> Hi Dave,
> 
> Sorry about my patches breaking your suspend-resume.
> 
> I, basically tried out building and booting 3.1 kernel with 
> my patch set to reproduce the failure. I could clearly
> see suspend not happening. It turns out to be 
> a bug with my first patch in global registration
> series submitted earlier.
> 
> e978aa7d7d57d04eb5f88a7507c4fb98577def77 / v3.1-1-ge978aa7
> 
> The following patch, fixes the suspend issues
> seen on my laptop due to earlier cpuidle cleanup 
> (Lenevo T420 booting with acpi_idle enabled). 
> Can you please give this a try
> on top of my patch set (without Rafael's fix) 
> and see if it fixes the problem for you. 
> I am not reverting acpi_idle_suspend flag and 
> hopefully it should resume fine too. 
> 
> ---
> 
> This patch fixes suspend-resume issue seen in the kernel 3.1
> series using acpi_idle_driver because of cpuidle global 
> registration cleanup.
> Here, when acpi_idle_suspend flag was set ( during suspend)
> the interrupts were not getting enabled in acpi_idle_enter_bm()
> routine which was causing the system to hang.
> 
> 
> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
> 
> ---
>  drivers/acpi/processor_idle.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 24fe3af..6e35293 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -895,8 +895,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
>  	if (unlikely(!pr))
>  		return -EINVAL;
> 
> -
>  	if (acpi_idle_suspend) {
> +		local_irq_disable();
> +		local_irq_enable();
>  		cpu_relax();
>  		return -EINVAL;
>  	}
> 
> Cheers,
> Deepthi
> 



-- 
Regards,
Srivatsa S. Bhat
IBM Linux Technology Center

Re: Suspend/resume regressions on Lenovo S10-3

[Dave Hansen]

On 06/11/2012 06:31 AM, Srivatsa S. Bhat wrote:
> Hi Dave,
> 
> On 06/06/2012 06:21 PM, Deepthi Dharwar wrote:
> 
>> On 05/28/2012 07:23 AM, Dave Hansen wrote:
>>
>>> I have a Lenovo S10-3 Atom netbook.  It's always had some amount of
>>> trouble working with the intel_idle driver, so I usually compile that
>>> out an use the acpi one.
> 
> 
> What problem did you face with intel_idle driver? Is it suspend/resume
> related?

With intel_idle, sometimes it won't boot, others it won't suspend/resume:

  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/674075

I'm actually not sure how it behaves on current kernels.