linux-kernel - Re: [PATCH] PM / suspend: Make cpuidle work in the "freeze" state

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <5354C082.6020908@linux.vnet.ibm.com>
Date:	Mon, 21 Apr 2014 12:23:54 +0530
From:	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
CC:	Linux PM list <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Zhang Rui <rui.zhang@...el.com>,
	Aubrey Li <aubrey.li@...el.com>
Subject: Re: [PATCH] PM / suspend: Make cpuidle work in the "freeze" state

On 04/21/2014 03:13 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.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@...el.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.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@...ux.vnet.ibm.com>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/