Suspend: Add config option to disable the freezer if architecture wants that

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>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

4 files changed, 40 insertions, 3 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 824140d6cd2..4a22c992861 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -405,6 +405,10 @@ config CMDLINE
           most cases you will need to specify the root device here.
 
 if !44x || BROKEN
+config ARCH_WANTS_FREEZER_CONTROL
+        def_bool y
+        depends on ADB_PMU
+
 source kernel/power/Kconfig
 endif
 
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index f8153fda06b..ef9b802738a 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -104,6 +104,17 @@ config SUSPEND
           powered and thus its contents are preserved, such as the
           suspend-to-RAM state (e.g. the ACPI S3 state).
 
+config SUSPEND_FREEZER
+        bool "Enable freezer for suspend to RAM/standby" \
+                if ARCH_WANTS_FREEZER_CONTROL || 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
         bool "Hibernation (aka 'suspend to disk')"
         depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
diff --git a/kernel/power/main.c b/kernel/power/main.c
index d9bba452764..e47214cfeb2 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -181,7 +181,7 @@ static int suspend_prepare(void)
 
         pm_prepare_console();
 
-        if (freeze_processes()) {
+        if (suspend_freeze_processes()) {
                 error = -EAGAIN;
                 goto Thaw;
         }
@@ -199,7 +199,7 @@ static int suspend_prepare(void)
                 return 0;
 
  Thaw:
-        thaw_processes();
+        suspend_thaw_processes();
         pm_restore_console();
  Finish:
         pm_notifier_call_chain(PM_POST_SUSPEND);
@@ -308,7 +308,7 @@ int suspend_devices_and_enter(suspend_state_t state)
  */
 static void suspend_finish(void)
 {
-        thaw_processes();
+        suspend_thaw_processes();
         pm_restore_console();
         pm_notifier_call_chain(PM_POST_SUSPEND);
 }
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 8ec5499c5ce..700f44ec840 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -1,6 +1,7 @@
 #include <linux/suspend.h>
 #include <linux/suspend_ioctls.h>
 #include <linux/utsname.h>
+#include <linux/freezer.h>
 
 struct swsusp_info {
         struct new_utsname      uts;
@@ -203,3 +204,24 @@ enum {
 #define TEST_MAX        (__TEST_AFTER_LAST - 1)
 
 extern int pm_test_level;
+
+#ifdef CONFIG_SUSPEND_FREEZER
+static inline int suspend_freeze_processes(void)
+{
+        return freeze_processes();
+}
+
+static inline void suspend_thaw_processes(void)
+{
+        thaw_processes();
+}
+#else
+static inline int suspend_freeze_processes(void)
+{
+        return 0;
+}
+
+static inline void suspend_thaw_processes(void)
+{
+}
+#endif