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>
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 7693e39..d971837 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -245,6 +245,7 @@
return unlikely(suspend_freeze_state == FREEZE_STATE_ENTER);
}
+extern void __init pm_states_init(void);
extern void freeze_set_ops(const struct platform_freeze_ops *ops);
extern void freeze_wake(void);
@@ -279,6 +280,7 @@
static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {}
static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; }
static inline bool idle_should_freeze(void) { return false; }
+static inline void __init pm_states_init(void) {}
static inline void freeze_set_ops(const struct platform_freeze_ops *ops) {}
static inline void freeze_wake(void) {}
#endif /* !CONFIG_SUSPEND */