* [PATCH] PM / suspend: Make cpuidle work in the "freeze" state
@ 2014-04-20 21:43 Rafael J. Wysocki
2014-04-21 6:53 ` Preeti U Murthy
0 siblings, 1 reply; 2+ messages in thread
From: Rafael J. Wysocki @ 2014-04-20 21:43 UTC (permalink / raw)
To: Linux PM list
Cc: Linux Kernel Mailing List, Zhang Rui, Aubrey Li, Preeti U Murthy
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)
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] PM / suspend: Make cpuidle work in the "freeze" state
2014-04-20 21:43 [PATCH] PM / suspend: Make cpuidle work in the "freeze" state Rafael J. Wysocki
@ 2014-04-21 6:53 ` Preeti U Murthy
0 siblings, 0 replies; 2+ messages in thread
From: Preeti U Murthy @ 2014-04-21 6:53 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Linux PM list, Linux Kernel Mailing List, Zhang Rui, Aubrey Li
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>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2014-04-21 6:53 ` Preeti U Murthy
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