From: Rafael J. Wysocki <[email protected]> Modify the ACPI system sleep support setup code to select suspend-to-idle as the default system sleep state if the ACPI_FADT_LOW_POWER_S0 flag is set in the FADT and the default sleep state was not selected from the kernel command line.
Signed-off-by: Rafael J. Wysocki <[email protected]> --- Documentation/power/states.txt | 4 +++- drivers/acpi/sleep.c | 8 ++++++++ include/linux/suspend.h | 2 ++ kernel/power/suspend.c | 4 ++-- 4 files changed, 15 insertions(+), 3 deletions(-) Index: linux-pm/include/linux/suspend.h =================================================================== --- linux-pm.orig/include/linux/suspend.h +++ linux-pm/include/linux/suspend.h @@ -194,6 +194,8 @@ struct platform_freeze_ops { }; #ifdef CONFIG_SUSPEND +extern suspend_state_t mem_sleep_default; + /** * suspend_set_ops - set platform dependent suspend operations * @ops: The new suspend operations to set. Index: linux-pm/drivers/acpi/sleep.c =================================================================== --- linux-pm.orig/drivers/acpi/sleep.c +++ linux-pm/drivers/acpi/sleep.c @@ -691,6 +691,14 @@ static void acpi_sleep_suspend_setup(voi if (acpi_sleep_state_supported(i)) sleep_states[i] = 1; + /* + * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set and + * the default suspend mode was not selected from the command line. + */ + if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0 && + mem_sleep_default > PM_SUSPEND_MEM) + mem_sleep_default = PM_SUSPEND_FREEZE; + suspend_set_ops(old_suspend_ordering ? &acpi_suspend_ops_old : &acpi_suspend_ops); freeze_set_ops(&acpi_freeze_ops); Index: linux-pm/kernel/power/suspend.c =================================================================== --- linux-pm.orig/kernel/power/suspend.c +++ linux-pm/kernel/power/suspend.c @@ -44,7 +44,7 @@ const char * const mem_sleep_labels[] = const char *mem_sleep_states[PM_SUSPEND_MAX]; suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE; -static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM; +suspend_state_t mem_sleep_default = PM_SUSPEND_MAX; unsigned int pm_suspend_global_flags; EXPORT_SYMBOL_GPL(pm_suspend_global_flags); @@ -163,7 +163,7 @@ void suspend_set_ops(const struct platfo } if (valid_state(PM_SUSPEND_MEM)) { mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM]; - if (mem_sleep_default == PM_SUSPEND_MEM) + if (mem_sleep_default >= PM_SUSPEND_MEM) mem_sleep_current = PM_SUSPEND_MEM; } Index: linux-pm/Documentation/power/states.txt =================================================================== --- linux-pm.orig/Documentation/power/states.txt +++ linux-pm/Documentation/power/states.txt @@ -35,7 +35,9 @@ only one way to cause the system to go i The default suspend mode (ie. the one to be used without writing anything into /sys/power/mem_sleep) is either "deep" (if Suspend-To-RAM is supported) or "s2idle", but it can be overridden by the value of the "mem_sleep_default" -parameter in the kernel command line. +parameter in the kernel command line. On some ACPI-based systems, depending on +the information in the FADT, the default may be "s2idle" even if Suspend-To-RAM +is supported. The properties of all of the sleep states are described below.
