[PATCH] PM: make freezer optional for suspend

Johannes Berg
2007-11-13T19:04:30Z

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
+ 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