From fa7fd6fa38e36d88bc9f2d0e45e5b9bd0387079f Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Fri, 19 Aug 2016 14:41:00 +0100 Subject: 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 Tested-by: Andy Gross Signed-off-by: Rafael J. Wysocki --- kernel/power/suspend.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'kernel/power/suspend.c') 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(); } -- cgit v1.2.3