[PATCH 1/4] PM / s2idle: Rearrange the main suspend-to-idle loop

From: Rafael J. Wysocki
Date: Thu Jul 20 2017 - 20:21:10 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

As a preparation for subsequent changes, rearrange the core
suspend-to-idle code by moving the initial invocation of
dpm_suspend_noirq() into s2idle_loop().

This also causes debug messages from that code to appear in
a less confusing order.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
kernel/power/power.h | 4 ++++
kernel/power/suspend.c | 26 +++++++++++++-------------
2 files changed, 17 insertions(+), 13 deletions(-)

Index: linux-pm/kernel/power/suspend.c
===================================================================
--- linux-pm.orig/kernel/power/suspend.c
+++ linux-pm/kernel/power/suspend.c
@@ -106,7 +106,13 @@ static void s2idle_loop(void)
{
pm_pr_dbg("suspend-to-idle\n");

- do {
+ while (!dpm_suspend_noirq(PMSG_SUSPEND)) {
+ /*
+ * Suspend-to-idle equals
+ * frozen processes + suspended devices + idle processors.
+ * Thus freeze_enter() should be called right after
+ * all devices have been suspended.
+ */
freeze_enter();

if (freeze_ops && freeze_ops->wake)
@@ -120,7 +126,7 @@ static void s2idle_loop(void)
break;

pm_wakeup_clear(false);
- } while (!dpm_suspend_noirq(PMSG_SUSPEND));
+ }

pm_pr_dbg("resume from suspend-to-idle\n");
}
@@ -377,6 +383,11 @@ static int suspend_enter(suspend_state_t
if (error)
goto Devices_early_resume;

+ if (state == PM_SUSPEND_FREEZE && pm_test_level != TEST_PLATFORM) {
+ s2idle_loop();
+ goto Platform_early_resume;
+ }
+
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
pr_err("PM: noirq suspend of devices failed\n");
@@ -389,17 +400,6 @@ static int suspend_enter(suspend_state_t
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;

- /*
- * PM_SUSPEND_FREEZE equals
- * frozen processes + suspended devices + idle processors.
- * Thus we should invoke freeze_enter() soon after
- * all the devices are suspended.
- */
- if (state == PM_SUSPEND_FREEZE) {
- s2idle_loop();
- goto Platform_early_resume;
- }
-
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
Index: linux-pm/kernel/power/power.h
===================================================================
--- linux-pm.orig/kernel/power/power.h
+++ linux-pm/kernel/power/power.h
@@ -245,7 +245,11 @@ enum {
#define TEST_FIRST TEST_NONE
#define TEST_MAX (__TEST_AFTER_LAST - 1)

+#ifdef CONFIG_PM_DEBUG
extern int pm_test_level;
+#else
+#define pm_test_level (TEST_NONE)
+#endif

#ifdef CONFIG_SUSPEND_FREEZER
static inline int suspend_freeze_processes(void)