Re: [PATCH] PM: make freezer optional for suspend

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, 13 of November 2007, Johannes Berg wrote:
> This patch makes the freezer optional for suspend to allow the
> system to work (or not work) like the original PMU suspend.
> 
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
> ---
> In a quick test, playing sound across suspend failed to work,
> it usually works when the freezer is enabled (unless you use
> gstreamer.)
> 
>  kernel/power/Kconfig |   10 ++++++++++
>  kernel/power/main.c  |    6 ++++++
>  2 files changed, 16 insertions(+)
> 
> --- everything.orig/kernel/power/main.c	2007-11-13 20:00:16.406263508 +0100
> +++ everything/kernel/power/main.c	2007-11-13 20:00:17.626268174 +0100
> @@ -79,10 +79,12 @@ static int suspend_prepare(void)
>  
>  	pm_prepare_console();
>  
> +#ifdef CONFIG_SUSPEND_FREEZER
>  	if (freeze_processes()) {
>  		error = -EAGAIN;
>  		goto Thaw;
>  	}
> +#endif
>  
>  	free_pages = global_page_state(NR_FREE_PAGES);
>  	if (free_pages < FREE_PAGE_NUMBER) {
> @@ -96,8 +98,10 @@ static int suspend_prepare(void)
>  	if (!error)
>  		return 0;
>  
> +#ifdef CONFIG_SUSPEND_FREEZER
>   Thaw:
>  	thaw_processes();
> +#endif
>  	pm_restore_console();
>   Finish:
>  	pm_notifier_call_chain(PM_POST_SUSPEND);
> @@ -191,7 +195,9 @@ int suspend_devices_and_enter(suspend_st
>   */
>  static void suspend_finish(void)
>  {
> +#ifdef CONFIG_SUSPEND_FREEZER
>  	thaw_processes();
> +#endif
>  	pm_restore_console();
>  	pm_notifier_call_chain(PM_POST_SUSPEND);
>  }
> --- everything.orig/kernel/power/Kconfig	2007-11-13 20:00:16.476274685 +0100
> +++ everything/kernel/power/Kconfig	2007-11-13 20:01:10.186257269 +0100
> @@ -97,6 +97,16 @@ config SUSPEND
>  	  powered and thus its contents are preserved, such as the
>  	  suspend-to-RAM state (i.e. the ACPI S3 state).
>  
> +config SUSPEND_FREEZER
> +	bool "Enable freezer for suspend to RAM/standby" if ADB_PMU || BROKEN

Hm, is ADB_PMU specific to powerpc?

> +	depends on SUSPEND
> +	default y
> +	help
> +	  This allows you to turn off the freezer for suspend. If this is
> +	  done, no tasks are frozen for suspend to RAM/standby.
> +
> +	  Turning OFF this setting is NOT recommended! If in doubt, say Y.
> +
>  config HIBERNATION_UP_POSSIBLE
>  	bool
>  	depends on X86 || PPC64_SWSUSP || PPC32

Greetings,
Rafael