Subject: [PATCH] cpuidle : fix random hangs with intel_idle

From: Daniel Lezcano <[email-masked]>
Date: Thu, 15 Mar 2012 01:09:41 +0100

The cpuidle consolidation inverts the local_irq_enable for
the poll_idle function with CPU_RELAX.

Signed-off-by: Daniel Lezcano <[email-masked]>
Reported-by: Hugh Dickins <[email-masked]>
---
 drivers/cpuidle/cpuidle.c |   21 +++++++++++++--------
 1 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 56de5f7..4869b55 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -213,20 +213,25 @@ int cpuidle_wrap_enter(struct cpuidle_device *dev,
 }
 
 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
-static inline int __poll_idle(struct cpuidle_device *dev,
+static int poll_idle(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index)
 {
+	ktime_t	t1, t2;
+	s64 diff;
+
+	t1 = ktime_get();
+	local_irq_enable();
 	while (!need_resched())
 		cpu_relax();
 
-	return index;
-}
+	t2 = ktime_get();
+	diff = ktime_to_us(ktime_sub(t2, t1));
+	if (diff > INT_MAX)
+		diff = INT_MAX;
 
-static int poll_idle(struct cpuidle_device *dev,
-		struct cpuidle_driver *drv, int index)
-{
-	return cpuidle_wrap_enter(dev,	drv, index,
-				__poll_idle);
+	dev->last_residency = (int) diff;
+
+	return index;
 }
 
 static void poll_idle_init(struct cpuidle_driver *drv)
-- 
1.7.5.4