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PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag 

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 <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@dell.com>
hifive-unleashed-5.1
Rafael J. Wysocki 2016-11-17 03:28:53 +01:00
parent 406e79385f
commit 08b98d3291
4 changed files with 15 additions and 3 deletions
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4
Documentation/power/states.txt
View File

@ -35,7 +35,9 @@ only one way to cause the system to go into the Suspend-To-RAM state (write
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.

8
drivers/acpi/sleep.c
View File

@ -691,6 +691,14 @@ static void acpi_sleep_suspend_setup(void)
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);

2
include/linux/suspend.h
View File

@ -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.

4
kernel/power/suspend.c
View File

@ -46,7 +46,7 @@ static 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);
@ -168,7 +168,7 @@ void suspend_set_ops(const struct platform_suspend_ops *ops)
}
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;
}