diff mbox

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

Message ID 4271849.XeOTooWnSN@vostro.rjw.lan (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Rafael J. Wysocki April 20, 2014, 9:43 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 kernel/power/suspend.c |    3 +++
 1 file changed, 3 insertions(+)


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Comments

preeti April 21, 2014, 6:53 a.m. UTC | #1 
On 04/21/2014 03:13 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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@intel.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  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)
> 
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>

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diff mbox

Patch

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)