From 9b6a68d94333cf19d4ec0f2aaf9f9eb68866630e Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey@neuling.org>
Date: Wed, 11 Jun 2014 15:59:27 +1000
Subject: [PATCH] powerpc/cpuidle: Only clear LPCR decrementer wakeup bit on
 fast sleep entry

Currently when entering fastsleep we clear all LPCR PECE bits.

This patch changes it to only clear the decrementer bit (ie. PECE1), which is
the only bit we really need to clear here.  This is needed if we want to set
other wakeup causes like the PECEDH bit so we can use hypervisor doorbells on
powernv.  Also we no longer clear the MER bit as it should never be set in the
host anyway.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 drivers/cpuidle/cpuidle-powernv.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 719f6fb5b1c35..74f5788d50b12 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -73,12 +73,10 @@ static int fastsleep_loop(struct cpuidle_device *dev,
 		return index;
 
 	new_lpcr = old_lpcr;
-	new_lpcr &= ~(LPCR_MER | LPCR_PECE); /* lpcr[mer] must be 0 */
-
-	/* exit powersave upon external interrupt, but not decrementer
-	 * interrupt.
+	/* Do not exit powersave upon decrementer as we've setup the timer
+	 * offload.
 	 */
-	new_lpcr |= LPCR_PECE0;
+	new_lpcr &= ~LPCR_PECE1;
 
 	mtspr(SPRN_LPCR, new_lpcr);
 	power7_sleep();