Commit 08b98d32 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarMario Limonciello <mario.limonciello@dell.com>
parent 406e7938

Documentation/power/states.txt

+3 −1
Original line number Diff line number Diff line
@@ -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.

drivers/acpi/sleep.c

+8 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/suspend.h

+2 −0
Original line number Diff line number Diff line
@@ -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.

kernel/power/suspend.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

	}

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