Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Daniel Lezcano]

On 05/30/2013 01:19 PM, Joseph Lo wrote:
> This supports CPU core power down on each CPU when CPU idle. When CPU go
> into this state, it saves it's context and needs a proper configuration
> in flow controller to power gate the CPU when CPU runs into WFI
> instruction. And the CPU also needs to set the IRQ as CPU power down idle
> wake up event in flow controller.
> 
> Signed-off-by: Joseph Lo <josephl@nvidia.com>
> ---

Hi Joseph,

a new flag has been added in the cpuidle framework to let this one to
handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP

It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c

You can get rid of the clockevent notify stuff by adding this flag to
the state.

Also, can you clarify why tegra3 code is used in tegra114 ?


>  arch/arm/mach-tegra/cpuidle-tegra114.c | 62 +++++++++++++++++++++++++++++++++-
>  1 file changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
> index 1d1c602..e7d21f5 100644
> --- a/arch/arm/mach-tegra/cpuidle-tegra114.c
> +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
> @@ -17,19 +17,79 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/cpuidle.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/clockchips.h>
>  
>  #include <asm/cpuidle.h>
> +#include <asm/suspend.h>
> +#include <asm/smp_plat.h>
> +
> +#include "pm.h"
> +#include "sleep.h"
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int tegra114_idle_power_down(struct cpuidle_device *dev,
> +				    struct cpuidle_driver *drv,
> +				    int index);

Isn't possible to move the driver declaration after the
tegra114_idle_power_down function, before the init function, so we
prevent a forward declaration ?

> +#define TEGRA114_MAX_STATES 2
> +#else
> +#define TEGRA114_MAX_STATES 1
> +#endif
>  
>  static struct cpuidle_driver tegra_idle_driver = {
>  	.name = "tegra_idle",
>  	.owner = THIS_MODULE,
> -	.state_count = 1,
> +	.state_count = TEGRA114_MAX_STATES,
>  	.states = {
>  		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
> +#ifdef CONFIG_PM_SLEEP
> +		[1] = {
> +			.enter			= tegra114_idle_power_down,
> +			.exit_latency		= 500,
> +			.target_residency	= 1000,
> +			.power_usage		= 0,
> +			.flags			= CPUIDLE_FLAG_TIME_VALID,
> +			.name			= "powered-down",
> +			.desc			= "CPU power gated",
> +		},
> +#endif
>  	},
>  };
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int tegra114_idle_power_down(struct cpuidle_device *dev,
> +				    struct cpuidle_driver *drv,
> +				    int index)
> +{
> +	u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;

IMO, it is up to the tegra_set_cpu_in_lp2 / tegra_clear_cpu_in_lp2
functions to do the cpu map conversion instead of adding this into a
routine working with logical cpu.

> +	local_fiq_disable();
> +
> +	tegra_set_cpu_in_lp2(cpu);
> +	cpu_pm_enter();
> +
> +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
> +	smp_wmb();

Why do you need a memory barrier here ?

> +	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
> +
> +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
> +
> +	cpu_pm_exit();
> +	tegra_clear_cpu_in_lp2(cpu);
> +
> +	local_fiq_enable();
> +
> +	smp_rmb();

Why do you need a memory barrier here ?

> +	return index;
> +}
> +#endif
> +
>  int __init tegra114_cpuidle_init(void)
>  {
> +#ifdef CONFIG_PM_SLEEP
> +	tegra_tear_down_cpu = tegra30_tear_down_cpu;
> +#endif

Doesn't this code should go in the pm.c file ?

>  	return cpuidle_register(&tegra_idle_driver, NULL);
>  }
> 


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Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Joseph Lo]

Hi Daniel,

Thanks for your review.

On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
> On 05/30/2013 01:19 PM, Joseph Lo wrote:
> > This supports CPU core power down on each CPU when CPU idle. When CPU go
> > into this state, it saves it's context and needs a proper configuration
> > in flow controller to power gate the CPU when CPU runs into WFI
> > instruction. And the CPU also needs to set the IRQ as CPU power down idle
> > wake up event in flow controller.
> > 
> > Signed-off-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > ---
> 
> Hi Joseph,
> 
> a new flag has been added in the cpuidle framework to let this one to
> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
> 
> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
> 
> You can get rid of the clockevent notify stuff by adding this flag to
> the state.
> 

I just tested this flag on Tegra20, 30 and 114. It is only OK on
Tegra20. It caused a warning message below on Tegra30/114 at boot time.

I gave it a quick check I found it can't clean
tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
code right now it's always OK. Not sure why? 

[   25.629539] ------------[ cut here ]------------
[   25.629559] WARNING: CPU: 2 PID: 0 at
kernel/time/tick-broadcast.c:578 tick_broadcast_oneshot_control
+0x1a4/0x1d0()
[   25.629565] Modules linked in:
[   25.629574] CPU: 2 PID: 0 Comm: swapper/2 Not tainted
3.10.0-rc3-next-20130529+ #15
[   25.629601] [<c00148f4>] (unwind_backtrace+0x0/0xf8) from
[<c0011040>] (show_stack+0x10/0x14)
[   25.629616] [<c0011040>] (show_stack+0x10/0x14) from [<c0504248>]
(dump_stack+0x80/0xc4)
[   25.629633] [<c0504248>] (dump_stack+0x80/0xc4) from [<c00231ac>]
(warn_slowpath_common+0x64/0x88)
[   25.629646] [<c00231ac>] (warn_slowpath_common+0x64/0x88) from
[<c00231ec>] (warn_slowpath_null+0x1c/0x24)
[   25.629657] [<c00231ec>] (warn_slowpath_null+0x1c/0x24) from
[<c00667f8>] (tick_broadcast_oneshot_control+0x1a4/0x1d0)
[   25.629670] [<c00667f8>] (tick_broadcast_oneshot_control+0x1a4/0x1d0)
from [<c0065cd0>] (tick_notify+0x240/0x40c)
[   25.629685] [<c0065cd0>] (tick_notify+0x240/0x40c) from [<c0044724>]
(notifier_call_chain+0x44/0x84)
[   25.629699] [<c0044724>] (notifier_call_chain+0x44/0x84) from
[<c0044828>] (raw_notifier_call_chain+0x18/0x20)
[   25.629712] [<c0044828>] (raw_notifier_call_chain+0x18/0x20) from
[<c00650cc>] (clockevents_notify+0x28/0x170)
[   25.629726] [<c00650cc>] (clockevents_notify+0x28/0x170) from
[<c033f1f0>] (cpuidle_idle_call+0x11c/0x168)
[   25.629739] [<c033f1f0>] (cpuidle_idle_call+0x11c/0x168) from
[<c000ea94>] (arch_cpu_idle+0x8/0x38)
[   25.629755] [<c000ea94>] (arch_cpu_idle+0x8/0x38) from [<c005ea80>]
(cpu_startup_entry+0x60/0x134)
[   25.629767] [<c005ea80>] (cpu_startup_entry+0x60/0x134) from
[<804fe9a4>] (0x804fe9a4)
[   25.629772] ---[ end trace 5484e77e2531bccc ]---


> Also, can you clarify why tegra3 code is used in tegra114 ?
> 
Yes, because the flow controller that was used to control CPU power is
similar for both SoCs. The function is shared for Tegra30/114.

> 
> >  arch/arm/mach-tegra/cpuidle-tegra114.c | 62 +++++++++++++++++++++++++++++++++-
> >  1 file changed, 61 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
> > index 1d1c602..e7d21f5 100644
> > --- a/arch/arm/mach-tegra/cpuidle-tegra114.c
> > +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
> > @@ -17,19 +17,79 @@
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> >  #include <linux/cpuidle.h>
> > +#include <linux/cpu_pm.h>
> > +#include <linux/clockchips.h>
> >  
> >  #include <asm/cpuidle.h>
> > +#include <asm/suspend.h>
> > +#include <asm/smp_plat.h>
> > +
> > +#include "pm.h"
> > +#include "sleep.h"
> > +
> > +#ifdef CONFIG_PM_SLEEP
> > +static int tegra114_idle_power_down(struct cpuidle_device *dev,
> > +				    struct cpuidle_driver *drv,
> > +				    int index);
> 
> Isn't possible to move the driver declaration after the
> tegra114_idle_power_down function, before the init function, so we
> prevent a forward declaration ?
> 
> > +#define TEGRA114_MAX_STATES 2
> > +#else
> > +#define TEGRA114_MAX_STATES 1
> > +#endif
> >  
> >  static struct cpuidle_driver tegra_idle_driver = {
> >  	.name = "tegra_idle",
> >  	.owner = THIS_MODULE,
> > -	.state_count = 1,
> > +	.state_count = TEGRA114_MAX_STATES,
> >  	.states = {
> >  		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
> > +#ifdef CONFIG_PM_SLEEP
> > +		[1] = {
> > +			.enter			= tegra114_idle_power_down,
> > +			.exit_latency		= 500,
> > +			.target_residency	= 1000,
> > +			.power_usage		= 0,
> > +			.flags			= CPUIDLE_FLAG_TIME_VALID,
> > +			.name			= "powered-down",
> > +			.desc			= "CPU power gated",
> > +		},
> > +#endif
> >  	},
> >  };
> >  
> > +#ifdef CONFIG_PM_SLEEP
> > +static int tegra114_idle_power_down(struct cpuidle_device *dev,
> > +				    struct cpuidle_driver *drv,
> > +				    int index)
> > +{
> > +	u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
> 
> IMO, it is up to the tegra_set_cpu_in_lp2 / tegra_clear_cpu_in_lp2
> functions to do the cpu map conversion instead of adding this into a
> routine working with logical cpu.
> 
Good idea, I can create another patch to do that.

> > +	local_fiq_disable();
> > +
> > +	tegra_set_cpu_in_lp2(cpu);
> > +	cpu_pm_enter();
> > +
> > +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
> > +	smp_wmb();
> 
> Why do you need a memory barrier here ?
> 
Yeah, Looks I don't have any static data that needs a barrier to sync
data for SMP here. Will remove them.

> > +	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
> > +
> > +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
> > +
> > +	cpu_pm_exit();
> > +	tegra_clear_cpu_in_lp2(cpu);
> > +
> > +	local_fiq_enable();
> > +
> > +	smp_rmb();
> 
> Why do you need a memory barrier here ?
> 
> > +	return index;
> > +}
> > +#endif
> > +
> >  int __init tegra114_cpuidle_init(void)
> >  {
> > +#ifdef CONFIG_PM_SLEEP
> > +	tegra_tear_down_cpu = tegra30_tear_down_cpu;
> > +#endif
> 
> Doesn't this code should go in the pm.c file ?
> 
Yes, I had a plan to do that too. Currently It had a timing issue about
this. Because the CPU idle driver was registered by device_initcall, but
the PM init function was registered at late init. I need to sync the
init time first.
OK, will do that too.

Thanks,
Joseph

Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Daniel Lezcano]

On 05/31/2013 11:12 AM, Joseph Lo wrote:
> Hi Daniel,
> 
> Thanks for your review.
> 
> On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
>> On 05/30/2013 01:19 PM, Joseph Lo wrote:
>>> This supports CPU core power down on each CPU when CPU idle. When CPU go
>>> into this state, it saves it's context and needs a proper configuration
>>> in flow controller to power gate the CPU when CPU runs into WFI
>>> instruction. And the CPU also needs to set the IRQ as CPU power down idle
>>> wake up event in flow controller.
>>>
>>> Signed-off-by: Joseph Lo <josephl@nvidia.com>
>>> ---
>>
>> Hi Joseph,
>>
>> a new flag has been added in the cpuidle framework to let this one to
>> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
>>
>> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
>>
>> You can get rid of the clockevent notify stuff by adding this flag to
>> the state.
>>
> 
> I just tested this flag on Tegra20, 30 and 114. It is only OK on
> Tegra20. It caused a warning message below on Tegra30/114 at boot time.
> 
> I gave it a quick check I found it can't clean
> tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
> code right now it's always OK. Not sure why? 

Is it possible you didn't intialized the timer broadcast with
CLOCK_EVT_NOTIFY_BROADCAST_ON in the driver and then this one is
actually disabled for you driver ?

> [   25.629539] ------------[ cut here ]------------
> [   25.629559] WARNING: CPU: 2 PID: 0 at
> kernel/time/tick-broadcast.c:578 tick_broadcast_oneshot_control
> +0x1a4/0x1d0()
> [   25.629565] Modules linked in:
> [   25.629574] CPU: 2 PID: 0 Comm: swapper/2 Not tainted
> 3.10.0-rc3-next-20130529+ #15
> [   25.629601] [<c00148f4>] (unwind_backtrace+0x0/0xf8) from
> [<c0011040>] (show_stack+0x10/0x14)
> [   25.629616] [<c0011040>] (show_stack+0x10/0x14) from [<c0504248>]
> (dump_stack+0x80/0xc4)
> [   25.629633] [<c0504248>] (dump_stack+0x80/0xc4) from [<c00231ac>]
> (warn_slowpath_common+0x64/0x88)
> [   25.629646] [<c00231ac>] (warn_slowpath_common+0x64/0x88) from
> [<c00231ec>] (warn_slowpath_null+0x1c/0x24)
> [   25.629657] [<c00231ec>] (warn_slowpath_null+0x1c/0x24) from
> [<c00667f8>] (tick_broadcast_oneshot_control+0x1a4/0x1d0)
> [   25.629670] [<c00667f8>] (tick_broadcast_oneshot_control+0x1a4/0x1d0)
> from [<c0065cd0>] (tick_notify+0x240/0x40c)
> [   25.629685] [<c0065cd0>] (tick_notify+0x240/0x40c) from [<c0044724>]
> (notifier_call_chain+0x44/0x84)
> [   25.629699] [<c0044724>] (notifier_call_chain+0x44/0x84) from
> [<c0044828>] (raw_notifier_call_chain+0x18/0x20)
> [   25.629712] [<c0044828>] (raw_notifier_call_chain+0x18/0x20) from
> [<c00650cc>] (clockevents_notify+0x28/0x170)
> [   25.629726] [<c00650cc>] (clockevents_notify+0x28/0x170) from
> [<c033f1f0>] (cpuidle_idle_call+0x11c/0x168)
> [   25.629739] [<c033f1f0>] (cpuidle_idle_call+0x11c/0x168) from
> [<c000ea94>] (arch_cpu_idle+0x8/0x38)
> [   25.629755] [<c000ea94>] (arch_cpu_idle+0x8/0x38) from [<c005ea80>]
> (cpu_startup_entry+0x60/0x134)
> [   25.629767] [<c005ea80>] (cpu_startup_entry+0x60/0x134) from
> [<804fe9a4>] (0x804fe9a4)
> [   25.629772] ---[ end trace 5484e77e2531bccc ]---
> 
> 
>> Also, can you clarify why tegra3 code is used in tegra114 ?
>>
> Yes, because the flow controller that was used to control CPU power is
> similar for both SoCs. The function is shared for Tegra30/114.
> 
>>
>>>  arch/arm/mach-tegra/cpuidle-tegra114.c | 62 +++++++++++++++++++++++++++++++++-
>>>  1 file changed, 61 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
>>> index 1d1c602..e7d21f5 100644
>>> --- a/arch/arm/mach-tegra/cpuidle-tegra114.c
>>> +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c
>>> @@ -17,19 +17,79 @@
>>>  #include <linux/kernel.h>
>>>  #include <linux/module.h>
>>>  #include <linux/cpuidle.h>
>>> +#include <linux/cpu_pm.h>
>>> +#include <linux/clockchips.h>
>>>  
>>>  #include <asm/cpuidle.h>
>>> +#include <asm/suspend.h>
>>> +#include <asm/smp_plat.h>
>>> +
>>> +#include "pm.h"
>>> +#include "sleep.h"
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int tegra114_idle_power_down(struct cpuidle_device *dev,
>>> +				    struct cpuidle_driver *drv,
>>> +				    int index);
>>
>> Isn't possible to move the driver declaration after the
>> tegra114_idle_power_down function, before the init function, so we
>> prevent a forward declaration ?
>>
>>> +#define TEGRA114_MAX_STATES 2
>>> +#else
>>> +#define TEGRA114_MAX_STATES 1
>>> +#endif
>>>  
>>>  static struct cpuidle_driver tegra_idle_driver = {
>>>  	.name = "tegra_idle",
>>>  	.owner = THIS_MODULE,
>>> -	.state_count = 1,
>>> +	.state_count = TEGRA114_MAX_STATES,
>>>  	.states = {
>>>  		[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
>>> +#ifdef CONFIG_PM_SLEEP
>>> +		[1] = {
>>> +			.enter			= tegra114_idle_power_down,
>>> +			.exit_latency		= 500,
>>> +			.target_residency	= 1000,
>>> +			.power_usage		= 0,
>>> +			.flags			= CPUIDLE_FLAG_TIME_VALID,
>>> +			.name			= "powered-down",
>>> +			.desc			= "CPU power gated",
>>> +		},
>>> +#endif
>>>  	},
>>>  };
>>>  
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int tegra114_idle_power_down(struct cpuidle_device *dev,
>>> +				    struct cpuidle_driver *drv,
>>> +				    int index)
>>> +{
>>> +	u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
>>
>> IMO, it is up to the tegra_set_cpu_in_lp2 / tegra_clear_cpu_in_lp2
>> functions to do the cpu map conversion instead of adding this into a
>> routine working with logical cpu.
>>
> Good idea, I can create another patch to do that.
> 
>>> +	local_fiq_disable();
>>> +
>>> +	tegra_set_cpu_in_lp2(cpu);
>>> +	cpu_pm_enter();
>>> +
>>> +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
>>> +	smp_wmb();
>>
>> Why do you need a memory barrier here ?
>>
> Yeah, Looks I don't have any static data that needs a barrier to sync
> data for SMP here. Will remove them.
> 
>>> +	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
>>> +
>>> +	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
>>> +
>>> +	cpu_pm_exit();
>>> +	tegra_clear_cpu_in_lp2(cpu);
>>> +
>>> +	local_fiq_enable();
>>> +
>>> +	smp_rmb();
>>
>> Why do you need a memory barrier here ?
>>
>>> +	return index;
>>> +}
>>> +#endif
>>> +
>>>  int __init tegra114_cpuidle_init(void)
>>>  {
>>> +#ifdef CONFIG_PM_SLEEP
>>> +	tegra_tear_down_cpu = tegra30_tear_down_cpu;
>>> +#endif
>>
>> Doesn't this code should go in the pm.c file ?
>>
> Yes, I had a plan to do that too. Currently It had a timing issue about
> this. Because the CPU idle driver was registered by device_initcall, but
> the PM init function was registered at late init. I need to sync the
> init time first.
> OK, will do that too.
> 
> Thanks,
> Joseph
> 
> 


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Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
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Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Joseph Lo]

On Fri, 2013-05-31 at 17:27 +0800, Daniel Lezcano wrote:
> On 05/31/2013 11:12 AM, Joseph Lo wrote:
> > Hi Daniel,
> > 
> > Thanks for your review.
> > 
> > On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
> >> On 05/30/2013 01:19 PM, Joseph Lo wrote:
> >>> This supports CPU core power down on each CPU when CPU idle. When CPU go
> >>> into this state, it saves it's context and needs a proper configuration
> >>> in flow controller to power gate the CPU when CPU runs into WFI
> >>> instruction. And the CPU also needs to set the IRQ as CPU power down idle
> >>> wake up event in flow controller.
> >>>
> >>> Signed-off-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >>> ---
> >>
> >> Hi Joseph,
> >>
> >> a new flag has been added in the cpuidle framework to let this one to
> >> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
> >>
> >> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
> >>
> >> You can get rid of the clockevent notify stuff by adding this flag to
> >> the state.
> >>
> > 
> > I just tested this flag on Tegra20, 30 and 114. It is only OK on
> > Tegra20. It caused a warning message below on Tegra30/114 at boot time.
> > 
> > I gave it a quick check I found it can't clean
> > tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
> > code right now it's always OK. Not sure why? 
> 
> Is it possible you didn't intialized the timer broadcast with
> CLOCK_EVT_NOTIFY_BROADCAST_ON in the driver and then this one is
> actually disabled for you driver ?
> 
I found if I don't apply the CPUIDLE_FLAG_TIMER_STOP flag, the function
"cpuidle_setup_broadcast_timer" (drivers/cpuidle/driver.c) would not be
called. Then it's OK.

If I apply this flag (with no CONFIG_CPU_IDLE_MULTIPLE_DRIVERS), the
cpuidle_register_driver only register for CPU0. Then the
"cpuidle_setup_broadcast_timer" only turn on for CPU0. I think this
might be the root cause. Not sure this also can reproduce on the other
SoCs?

Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Joseph Lo]

On Fri, 2013-05-31 at 18:47 +0800, Joseph Lo wrote:
> On Fri, 2013-05-31 at 17:27 +0800, Daniel Lezcano wrote:
> > On 05/31/2013 11:12 AM, Joseph Lo wrote:
> > > Hi Daniel,
> > > 
> > > Thanks for your review.
> > > 
> > > On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
> > >> On 05/30/2013 01:19 PM, Joseph Lo wrote:
> > >>> This supports CPU core power down on each CPU when CPU idle. When CPU go
> > >>> into this state, it saves it's context and needs a proper configuration
> > >>> in flow controller to power gate the CPU when CPU runs into WFI
> > >>> instruction. And the CPU also needs to set the IRQ as CPU power down idle
> > >>> wake up event in flow controller.
> > >>>
> > >>> Signed-off-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > >>> ---
> > >>
> > >> Hi Joseph,
> > >>
> > >> a new flag has been added in the cpuidle framework to let this one to
> > >> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
> > >>
> > >> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
> > >>
> > >> You can get rid of the clockevent notify stuff by adding this flag to
> > >> the state.
> > >>
> > > 
> > > I just tested this flag on Tegra20, 30 and 114. It is only OK on
> > > Tegra20. It caused a warning message below on Tegra30/114 at boot time.
> > > 
> > > I gave it a quick check I found it can't clean
> > > tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
> > > code right now it's always OK. Not sure why? 
> > 
> > Is it possible you didn't intialized the timer broadcast with
> > CLOCK_EVT_NOTIFY_BROADCAST_ON in the driver and then this one is
> > actually disabled for you driver ?
> > 
> I found if I don't apply the CPUIDLE_FLAG_TIMER_STOP flag, the function
> "cpuidle_setup_broadcast_timer" (drivers/cpuidle/driver.c) would not be
> called. Then it's OK.
> 
> If I apply this flag (with no CONFIG_CPU_IDLE_MULTIPLE_DRIVERS), the
> cpuidle_register_driver only register for CPU0. Then the
> "cpuidle_setup_broadcast_timer" only turn on for CPU0. I think this
> might be the root cause. Not sure this also can reproduce on the other
> SoCs?
> 
Looks it's not related to CLOCK_EVT_NOTIFY_BROADCAST_ON. I still saw the
warning message even enable CONFIG_CPU_IDLE_MULTIPLE_DRIVERS. But if I
move the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT from idle
framework back to driver, then everything is OK.

Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Joseph Lo]

On Fri, 2013-05-31 at 19:31 +0800, Joseph Lo wrote:
> On Fri, 2013-05-31 at 18:47 +0800, Joseph Lo wrote:
> > On Fri, 2013-05-31 at 17:27 +0800, Daniel Lezcano wrote:
> > > On 05/31/2013 11:12 AM, Joseph Lo wrote:
> > > > Hi Daniel,
> > > > 
> > > > Thanks for your review.
> > > > 
> > > > On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
> > > >> On 05/30/2013 01:19 PM, Joseph Lo wrote:
> > > >>> This supports CPU core power down on each CPU when CPU idle. When CPU go
> > > >>> into this state, it saves it's context and needs a proper configuration
> > > >>> in flow controller to power gate the CPU when CPU runs into WFI
> > > >>> instruction. And the CPU also needs to set the IRQ as CPU power down idle
> > > >>> wake up event in flow controller.
> > > >>>
> > > >>> Signed-off-by: Joseph Lo <josephl@nvidia.com>
> > > >>> ---
> > > >>
> > > >> Hi Joseph,
> > > >>
> > > >> a new flag has been added in the cpuidle framework to let this one to
> > > >> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
> > > >>
> > > >> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
> > > >>
> > > >> You can get rid of the clockevent notify stuff by adding this flag to
> > > >> the state.
> > > >>
> > > > 
> > > > I just tested this flag on Tegra20, 30 and 114. It is only OK on
> > > > Tegra20. It caused a warning message below on Tegra30/114 at boot time.
> > > > 
> > > > I gave it a quick check I found it can't clean
> > > > tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
> > > > code right now it's always OK. Not sure why? 
> > > 
> > > Is it possible you didn't intialized the timer broadcast with
> > > CLOCK_EVT_NOTIFY_BROADCAST_ON in the driver and then this one is
> > > actually disabled for you driver ?
> > > 
> > I found if I don't apply the CPUIDLE_FLAG_TIMER_STOP flag, the function
> > "cpuidle_setup_broadcast_timer" (drivers/cpuidle/driver.c) would not be
> > called. Then it's OK.
> > 
> > If I apply this flag (with no CONFIG_CPU_IDLE_MULTIPLE_DRIVERS), the
> > cpuidle_register_driver only register for CPU0. Then the
> > "cpuidle_setup_broadcast_timer" only turn on for CPU0. I think this
> > might be the root cause. Not sure this also can reproduce on the other
> > SoCs?
> > 
> Looks it's not related to CLOCK_EVT_NOTIFY_BROADCAST_ON. I still saw the
> warning message even enable CONFIG_CPU_IDLE_MULTIPLE_DRIVERS. But if I
> move the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT from idle
> framework back to driver, then everything is OK.
> 
Once I move the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT
right after "local_irq_enable" in the
"cpuidle_enter_state" (drivers/cpuidle/cpuidle.c). Then the warning
message shows up.

Re: [PATCH 3/3] ARM: tegra114: cpuidle: add powered-down state

[Daniel Lezcano]

On 05/31/2013 01:44 PM, Joseph Lo wrote:
> On Fri, 2013-05-31 at 19:31 +0800, Joseph Lo wrote:
>> On Fri, 2013-05-31 at 18:47 +0800, Joseph Lo wrote:
>>> On Fri, 2013-05-31 at 17:27 +0800, Daniel Lezcano wrote:
>>>> On 05/31/2013 11:12 AM, Joseph Lo wrote:
>>>>> Hi Daniel,
>>>>>
>>>>> Thanks for your review.
>>>>>
>>>>> On Thu, 2013-05-30 at 22:35 +0800, Daniel Lezcano wrote:
>>>>>> On 05/30/2013 01:19 PM, Joseph Lo wrote:
>>>>>>> This supports CPU core power down on each CPU when CPU idle. When CPU go
>>>>>>> into this state, it saves it's context and needs a proper configuration
>>>>>>> in flow controller to power gate the CPU when CPU runs into WFI
>>>>>>> instruction. And the CPU also needs to set the IRQ as CPU power down idle
>>>>>>> wake up event in flow controller.
>>>>>>>
>>>>>>> Signed-off-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>>>>>> ---
>>>>>>
>>>>>> Hi Joseph,
>>>>>>
>>>>>> a new flag has been added in the cpuidle framework to let this one to
>>>>>> handle the timer broadcast : CPUIDLE_FLAG_TIMER_STOP
>>>>>>
>>>>>> It is the commit b60e6a0eb0273132cbb60a9806abf5f47a4aee1c
>>>>>>
>>>>>> You can get rid of the clockevent notify stuff by adding this flag to
>>>>>> the state.
>>>>>>
>>>>>
>>>>> I just tested this flag on Tegra20, 30 and 114. It is only OK on
>>>>> Tegra20. It caused a warning message below on Tegra30/114 at boot time.
>>>>>
>>>>> I gave it a quick check I found it can't clean
>>>>> tick_broadcast_pending_mask sometimes if apply the flag. But I keep the
>>>>> code right now it's always OK. Not sure why? 
>>>>
>>>> Is it possible you didn't intialized the timer broadcast with
>>>> CLOCK_EVT_NOTIFY_BROADCAST_ON in the driver and then this one is
>>>> actually disabled for you driver ?
>>>>
>>> I found if I don't apply the CPUIDLE_FLAG_TIMER_STOP flag, the function
>>> "cpuidle_setup_broadcast_timer" (drivers/cpuidle/driver.c) would not be
>>> called. Then it's OK.
>>>
>>> If I apply this flag (with no CONFIG_CPU_IDLE_MULTIPLE_DRIVERS), the
>>> cpuidle_register_driver only register for CPU0. Then the
>>> "cpuidle_setup_broadcast_timer" only turn on for CPU0. I think this
>>> might be the root cause. Not sure this also can reproduce on the other
>>> SoCs?
>>>
>> Looks it's not related to CLOCK_EVT_NOTIFY_BROADCAST_ON. I still saw the
>> warning message even enable CONFIG_CPU_IDLE_MULTIPLE_DRIVERS. But if I
>> move the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT from idle
>> framework back to driver, then everything is OK.
>>
> Once I move the clockevent_notify of CLOCK_EVT_NOTIFY_BROADCAST_EXIT
> right after "local_irq_enable" in the
> "cpuidle_enter_state" (drivers/cpuidle/cpuidle.c). Then the warning
> message shows up.

Is it possible you pastebin you kernel config file ? I would like to
check a couple of things before investigating the code.

Thanks


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