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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linux PM list <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: [PATCH 2/4] cpuidle: Check the sign of index in cpuidle_reflect()
Date: Mon, 04 May 2015 15:57:01 +0200	[thread overview]
Message-ID: <1452615.qnuzHTbuFj@vostro.rjw.lan> (raw)
In-Reply-To: <3084951.QaIkFrZ3VU@vostro.rjw.lan>

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Avoid calling the governor's ->reflect method if the state index
passed to cpuidle_reflect() is negative.

This allows the analogous check to be dropped from menu_reflect(),
so do that too, and ensures that arbitrary error codes can be
passed to cpuidle_reflect() as the index with no adverse
consequences.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpuidle/cpuidle.c        |    2 +-
 drivers/cpuidle/governors/menu.c |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/cpuidle.c
+++ linux-pm/drivers/cpuidle/cpuidle.c
@@ -249,7 +249,7 @@ int cpuidle_enter(struct cpuidle_driver
  */
 void cpuidle_reflect(struct cpuidle_device *dev, int index)
 {
-	if (cpuidle_curr_governor->reflect)
+	if (cpuidle_curr_governor->reflect && index >= 0)
 		cpuidle_curr_governor->reflect(dev, index);
 }
 
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -367,9 +367,9 @@ static int menu_select(struct cpuidle_dr
 static void menu_reflect(struct cpuidle_device *dev, int index)
 {
 	struct menu_device *data = this_cpu_ptr(&menu_devices);
+
 	data->last_state_idx = index;
-	if (index >= 0)
-		data->needs_update = 1;
+	data->needs_update = 1;
 }
 
 /**


  parent reply	other threads:[~2015-05-04 13:35 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-04 13:54 [PATCH 0/4] sched / idle: Reduce the number of branches in the idle loop Rafael J. Wysocki
2015-05-04 13:56 ` [PATCH 1/4] sched / idle: Move the default idle call code to a separate function Rafael J. Wysocki
2015-05-04 14:00   ` Daniel Lezcano
2015-05-04 14:22   ` Peter Zijlstra
2015-05-04 21:08     ` Rafael J. Wysocki
2015-05-04 13:57 ` Rafael J. Wysocki [this message]
2015-05-04 14:02   ` [PATCH 2/4] cpuidle: Check the sign of index in cpuidle_reflect() Daniel Lezcano
2015-05-04 13:57 ` [PATCH 3/4] sched / idle: Eliminate the "reflect" check from cpuidle_idle_call() Rafael J. Wysocki
2015-05-04 14:49   ` Daniel Lezcano
2015-05-04 13:58 ` [PATCH 4/4] sched / idle: Call default_idle_call() from cpuidle_enter_state() Rafael J. Wysocki
2015-05-04 15:04   ` Daniel Lezcano
2015-05-04 21:11     ` Rafael J. Wysocki
2015-05-04 14:25 ` [PATCH 0/4] sched / idle: Reduce the number of branches in the idle loop Peter Zijlstra
2015-05-04 21:23   ` Rafael J. Wysocki

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