From mboxrd@z Thu Jan  1 00:00:00 1970
From: daniel.lezcano@linaro.org (Daniel Lezcano)
Date: Mon, 07 Jan 2013 09:54:13 +0100
Subject: [PATCH 1/1] ARM: ux500:mach-ux500/cpuidle.c spinlock dis-matching
In-Reply-To: <CAKvkGKcPumpRcxQrwWGXoWvG4Sk2niTiojfNU=2PnZ9zq_7EcQ@mail.gmail.com>
References: <CAKvkGKdoWxmnRbNvn_SikRhzsyyzqEC99XtSM9ZeaVGjEA_Ydw@mail.gmail.com>
 <50E9A4FE.6090807@linaro.org>
 <CAKvkGKcPumpRcxQrwWGXoWvG4Sk2niTiojfNU=2PnZ9zq_7EcQ@mail.gmail.com>
Message-ID: <50EA8D35.5020501@linaro.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 01/07/2013 06:50 AM, steve.zhan wrote:
> Hi Daniel,
> 
>     Happy new year, Thank you for reply.
> Sorry for that i have refer the old patch email.
> I have updated the patch, Pls check the URL:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2012-December/138939.html
> Now i am using gmail GUI tools to send mail, i will switch email tool
> to MUTT to commit the other patchs in the future.

Ok.

Please do not introduce a new variable which is at the end pointless and
add more complexity.

You can simply remove the if statement for prcmu_gic_decouple(), or
unlock if it fails.

Thanks
  -- Daniel

> --------------
> steve.zhan
> 
> 2013/1/7, Daniel Lezcano <daniel.lezcano@linaro.org>:
>> On 12/28/2012 08:06 AM, steve.zhan wrote:
>>> Hi Daniel,
>>
>> Hi Steve,
>>
>> sorry I missed your email.
>>
>>>
>>>        I think we must unlock the master spinlock even
>>> prcmu_gic_decouple function now always return 0.
>>>        Could you give some infos about this?
>>
>> I agree, that would be cleaner.
>>
>> AFAICS, your patch does not solve the problem because 'recouple' will be
>> false if prcmu_gic_decouple fails, so the lock will never be release.
>>
>> That will be simpler to do:
>>
>> if (prcmu_gic_decouple()) {
>> 	spin_unlock(&master);
>> 	goto out;
>> }
>>
>> no ?
>>
>>> Thanks.
>>>
>>> diff --git a/arch/arm/mach-ux500/cpuidle.c
>>> b/arch/arm/mach-ux500/cpuidle.c
>>> index b54884bd..b0759ce 100644
>>> --- a/arch/arm/mach-ux500/cpuidle.c
>>> +++ b/arch/arm/mach-ux500/cpuidle.c
>>> @@ -29,6 +29,7 @@ static inline int ux500_enter_idle(struct cpuidle_device
>>> *dev,
>>>  {
>>>         int this_cpu = smp_processor_id();
>>>         bool recouple = false;
>>> +       bool locked = false;
>>>
>>>         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &this_cpu);
>>>
>>> @@ -39,6 +40,8 @@ static inline int ux500_enter_idle(struct cpuidle_device
>>> *dev,
>>>                 if (!spin_trylock(&master_lock))
>>>                         goto wfi;
>>>
>>> +               locked = true;
>>> +
>>>                 /* decouple the gic from the A9 cores */
>>>                 if (prcmu_gic_decouple())
>>>                         goto out;
>>> @@ -76,7 +79,7 @@ static inline int ux500_enter_idle(struct cpuidle_device
>>> *dev,
>>>                 /* When we switch to retention, the prcmu is in charge
>>>                  * of recoupling the gic automatically */
>>>                 recouple = false;
>>> -
>>> +               locked = false;
>>>                 spin_unlock(&master_lock);
>>>         }
>>>  wfi:
>>> @@ -86,7 +89,8 @@ out:
>>>
>>>         if (recouple) {
>>>                 prcmu_gic_recouple();
>>> -               spin_unlock(&master_lock);
>>> +               if (locked)
>>> +                       spin_unlock(&master_lock);
>>>         }
>>>
>>>         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &this_cpu);
>>>
>>>
>>>
>>> Steve Zhan
>>>
>>
>>
>> --
>>  <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs
>>
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>>
>>
> 
> 


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