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authorSudeep Holla <Sudeep.Holla@arm.com>2016-08-19 14:41:00 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-09-13 02:17:19 +0200
commitfa7fd6fa38e36d88bc9f2d0e45e5b9bd0387079f (patch)
tree21c9156a38c00468ba0b3a332282f101055f03c4 /kernel/power
parent5b3f249c94ce1f46bacd9814385b0ee2d1ae52f3 (diff)
PM / sleep: enable suspend-to-idle even without registered suspend_ops
Suspend-to-idle (aka the "freeze" sleep state) is a system sleep state in which all of the processors enter deepest possible idle state and wait for interrupts right after suspending all the devices. There is no hard requirement for a platform to support and register platform specific suspend_ops to enter suspend-to-idle/freeze state. Only deeper system sleep states like PM_SUSPEND_STANDBY and PM_SUSPEND_MEM rely on such low level support/implementation. suspend-to-idle can be entered as along as all the devices can be suspended. This patch enables the support for suspend-to-idle even on systems that don't have any low level support for deeper system sleep states and/or don't register any platform specific suspend_ops. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Andy Gross <andy.gross@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/main.c1
-rw-r--r--kernel/power/suspend.c14
2 files changed, 12 insertions, 3 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 5ea50b1b7595..281a697fd458 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -644,6 +644,7 @@ static int __init pm_init(void)
return error;
hibernate_image_size_init();
hibernate_reserved_size_init();
+ pm_states_init();
power_kobj = kobject_create_and_add("power", NULL);
if (!power_kobj)
return -ENOMEM;
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 0acab9d7f96f..1e7f5da648d9 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -118,10 +118,18 @@ static bool valid_state(suspend_state_t state)
*/
static bool relative_states;
+void __init pm_states_init(void)
+{
+ /*
+ * freeze state should be supported even without any suspend_ops,
+ * initialize pm_states accordingly here
+ */
+ pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
+}
+
static int __init sleep_states_setup(char *str)
{
relative_states = !strncmp(str, "1", 1);
- pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
return 1;
}
@@ -211,7 +219,7 @@ static int platform_suspend_begin(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
return freeze_ops->begin();
- else if (suspend_ops->begin)
+ else if (suspend_ops && suspend_ops->begin)
return suspend_ops->begin(state);
else
return 0;
@@ -221,7 +229,7 @@ static void platform_resume_end(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
freeze_ops->end();
- else if (suspend_ops->end)
+ else if (suspend_ops && suspend_ops->end)
suspend_ops->end();
}