From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 6 Mar 2013 11:18:37 +0000 (+0000)
Subject: arm: Use tick broadcast expired check
X-Git-Tag: v3.10-rc1~171^2~30
X-Git-Url: http://git.cascardo.info/?a=commitdiff_plain;h=80bbe9f273a38f83ecfc50fe384a57f8428887bd;p=cascardo%2Flinux.git

arm: Use tick broadcast expired check

Avoid going back into deep idle if the tick broadcast IPI is about to
fire.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: LAK <linux-arm-kernel@lists.infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Jason Liu <liu.h.jason@gmail.com>
Link: http://lkml.kernel.org/r/20130306111537.640722922@linutronix.de
---

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 047d3e40e470..db4ffd09ee23 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -199,7 +199,16 @@ void cpu_idle(void)
 #ifdef CONFIG_PL310_ERRATA_769419
 			wmb();
 #endif
-			if (hlt_counter) {
+			/*
+			 * In poll mode we reenable interrupts and spin.
+			 *
+			 * Also if we detected in the wakeup from idle
+			 * path that the tick broadcast device expired
+			 * for us, we don't want to go deep idle as we
+			 * know that the IPI is going to arrive right
+			 * away
+			 */
+			if (hlt_counter || tick_check_broadcast_expired()) {
 				local_irq_enable();
 				cpu_relax();
 			} else if (!need_resched()) {