[PATCH] PM / suspend: Make cpuidle work in the "freeze" state

From: Rafael J. Wysocki
Date: Sun Apr 20 2014 - 17:26:52 EST


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

The "freeze" system sleep state introduced by commit 7e73c5ae6e79
(PM: Introduce suspend state PM_SUSPEND_FREEZE) requires cpuidle
to be functional when freeze_enter() is executed to work correctly
(that is, to be able to save any more energy than runtime idle),
but that is impossible after commit 8651f97bd951d (PM / cpuidle:
System resume hang fix with cpuidle) which caused cpuidle to be
paused in dpm_suspend_noirq() and resumed in dpm_resume_noirq().

To avoid that problem, add cpuidle_resume() and cpuidle_pause()
to the beginning and the end of freeze_enter(), respectively.

Reported-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
kernel/power/suspend.c | 3 +++
1 file changed, 3 insertions(+)

Index: linux-pm/kernel/power/suspend.c
===================================================================
--- linux-pm.orig/kernel/power/suspend.c
+++ linux-pm/kernel/power/suspend.c
@@ -14,6 +14,7 @@
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
+#include <linux/cpuidle.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
#include <linux/io.h>
@@ -53,7 +54,9 @@ static void freeze_begin(void)

static void freeze_enter(void)
{
+ cpuidle_resume();
wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+ cpuidle_pause();
}

void freeze_wake(void)

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