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From: rnayak@ti•com (Rajendra Nayak)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC 2/4] ARM: OMAP: PM: Get rid of Powerdomain book-keeping from cpuidle
Date: Fri, 20 Jul 2012 13:38:42 +0530	[thread overview]
Message-ID: <5009120A.1060400@ti.com> (raw)
In-Reply-To: <CAMQu2gyCmx57ctZFBoAUKUXY+9zwFLCDHsBfehXicH7mEyDzQg@mail.gmail.com>

On Friday 20 July 2012 12:55 PM, Shilimkar, Santosh wrote:
> On Fri, Jul 20, 2012 at 11:34 AM, Rajendra Nayak<rnayak@ti•com>  wrote:
>> pwrdm_pre_transition()/pwrdm_post_transition() have always been high latency
>> operations done within cpuidle to do Powerdomain level book-keeping to know
>> what state transitions for different Powerdomains have been triggered.
>> This is also useful to do a restore-on-demand in some cases when we know
>> the context for the given Powerdomain was lost etc.
>>
>> Now that we have definitive entry/exit points (thanks to the Powerdomain
>> level usecounting) for Powerdomain transitions, these book-keeping functions
>> can very well be moved from within CPUidle into pwrdm_clkdm_enable()/pwrdm_
>> clkdm_disable() functions.
>>
>> Also rename _pwrdm_pre/post_transition_cb() to pwrdm_pre/post_transition()
>> and get rid of the original ones which iterate over all powerdomains.
>>
>> Signed-off-by: Rajendra Nayak<rnayak@ti•com>
>> ---
>>   arch/arm/mach-omap2/omap-mpuss-lowpower.c |    4 ++--
>>   arch/arm/mach-omap2/pm34xx.c              |    4 ++--
>>   arch/arm/mach-omap2/powerdomain.c         |   28 ++++++++--------------------
>>   arch/arm/mach-omap2/powerdomain.h         |    4 ++--
>>   4 files changed, 14 insertions(+), 26 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> index 13670aa..ea19439 100644
>> --- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> +++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> @@ -255,7 +255,7 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
>>                  return -ENXIO;
>>          }
>>
>> -       pwrdm_pre_transition();
>> +       pwrdm_cpu_idle();
>>
> Glad to see this is getting optimized.
> I haven't seen how "pwrdm_cpu_[idle/wakeup]()" is
> implemented but will those work on SMP system ?
> I mean OMAP4, any CPU can make this call ?

Thats a good question. I think Tero did this so he can kick in
voltage transitions at the right time in idle/suspend.
Given that these deal with incrementing/decrementing the MPU and CORE
pwrdm usecounts alone, maybe on OMAP4 (SMP systems) this needs to also
increment/decrement the specific CPU usecounts on the CPUs these calls
are made.

>
> Regards
> Santosh

  reply	other threads:[~2012-07-20  8:08 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-20  6:04 [RFC 0/4] OMAP Cpuidle/Suspend Cleanups Rajendra Nayak
2012-07-20  6:04 ` [RFC 1/4] ARM: OMAP3: cpuidle: Remove unused MPU OSWR support code Rajendra Nayak
2012-07-20  7:08   ` Shilimkar, Santosh
2012-07-20 18:25   ` Paul Walmsley
2012-07-23  7:10     ` Rajendra Nayak
2012-07-20  6:04 ` [RFC 2/4] ARM: OMAP: PM: Get rid of Powerdomain book-keeping from cpuidle Rajendra Nayak
2012-07-20  7:25   ` Shilimkar, Santosh
2012-07-20  8:08     ` Rajendra Nayak [this message]
2012-07-20  8:51       ` Tero Kristo
2012-07-20 11:54         ` Shilimkar, Santosh
2012-07-25 22:43         ` Kevin Hilman
2012-07-26 11:43           ` Rajendra Nayak
2012-07-26 12:42           ` Rajendra Nayak
2012-07-26 17:44             ` Kevin Hilman
2012-07-26 18:27               ` Tero Kristo
2012-07-26 20:50                 ` Paul Walmsley
2012-07-27  6:46                 ` Rajendra Nayak
2012-07-27  7:43                   ` Rajendra Nayak
2012-07-20  6:04 ` [RFC 3/4] ARM: OMAP: powerdomain: Add .power_on/.power_down hooks for powerdomains Rajendra Nayak
2012-07-20  7:26   ` Shilimkar, Santosh
2012-07-20  6:04 ` [RFC 4/4] ARM: OMAP3: PM: Use .power_on/.power_down to clean omap_sram_idle Rajendra Nayak
2012-07-20  7:30   ` Shilimkar, Santosh
2012-07-20  8:59 ` [RFC 0/4] OMAP Cpuidle/Suspend Cleanups Tero Kristo
2012-07-20  9:03   ` Rajendra Nayak

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