ARM: ux500:mach-ux500/cpuidle.c spinlock dis-matching

Hi Daniel,Linus Walleij.
	Using MUTT resubmit this for 
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/139893.html

---
Steve

commit 99d0a05d163bd070eba7caab7e772206edbcbbc9
Author: steve zhan [off-list ref]
Date:   Mon Jan 7 18:19:14 2013 +0800

    ARM: ux500: add spin_unlock(&master_lock).
    
    Add the missing spin_unlock statement to unlock
    master_lock when prcmu_gic_decouple() return TRUE
    
    Signed-off-by: steve zhan [off-list ref]

diff --git a/arch/arm/mach-ux500/cpuidle.c b/arch/arm/mach-ux500/cpuidle.c
index b54884bd..ce91493 100644
--- a/arch/arm/mach-ux500/cpuidle.c
+++ b/arch/arm/mach-ux500/cpuidle.c

@@ -40,8 +40,10 @@ static inline int ux500_enter_idle(struct cpuidle_device *dev,
 			goto wfi;
 
 		/* decouple the gic from the A9 cores */
-		if (prcmu_gic_decouple())
+		if (prcmu_gic_decouple()) {
+			spin_unlock(&master_lock);
 			goto out;
+		}
 
 		/* If an error occur, we will have to recouple the gic
 		 * manually */

2013/1/7 Daniel Lezcano [off-list ref]:

On 01/07/2013 06:50 AM, steve.zhan wrote:

quoted

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

quoted

--------------
steve.zhan

2013/1/7, Daniel Lezcano [off-list ref]:

quoted

On 12/28/2012 08:06 AM, steve.zhan wrote:

quoted

Hi Daniel,

Hi Steve,

sorry I missed your email.

quoted

       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 ?

quoted

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

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