[PATCH] powerpc/pseries: fix idle sleep early exit state

[Sebastien Dugue]

  In pseries_dedicated_idle_sleep(), if we need to exit idle during the
snooze period (i.e. need_resched or cpu has been offlined), then we should
re-disable the interrupts and clear TIF_POLLING_NRFLAG before leaving.

Signed-off-by: Sebastien Dugue <sebastien.dugue at bull.net>
Cc: Paul Mackerras <paulus at samba.org>
---
 arch/powerpc/platforms/pseries/setup.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index ec34170..8270f04 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -504,8 +504,13 @@ static void pseries_dedicated_idle_sleep(void)
 		set_thread_flag(TIF_POLLING_NRFLAG);
 
 		while (get_tb() < start_snooze) {
-			if (need_resched() || cpu_is_offline(cpu))
-				goto out;
+			if (need_resched() || cpu_is_offline(cpu)) {
+				HMT_medium();
+				clear_thread_flag(TIF_POLLING_NRFLAG);
+				smp_mb();
+				local_irq_disable();
+				goto out2;
+			}
 			ppc64_runlatch_off();
 			HMT_low();
 			HMT_very_low();
@@ -523,6 +528,7 @@ static void pseries_dedicated_idle_sleep(void)
 
 out:
 	HMT_medium();
+out2:
 	out_purr = mfspr(SPRN_PURR);
 	get_lppaca()->wait_state_cycles += out_purr - in_purr;
 	get_lppaca()->donate_dedicated_cpu = 0;
-- 
1.6.0.1.308.gede4c