path: root/kernel
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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-07-31 23:43:18 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-08-05 01:51:26 +0200
commite870c6c87cf9484090d28f2a68aa29e008960c93 (patch)
tree9d19e498e1ed8bcc864b66d5817f03d09cc6ddcd /kernel
parent635173a17b0323c28a39fb06fa36d876035cd2b9 (diff)
ACPI / PM: Prefer suspend-to-idle over S3 on some systems
Modify the ACPI system sleep support setup code to select suspend-to-idle as the default system sleep state if (1) the ACPI_FADT_LOW_POWER_S0 flag is set in the FADT and (2) the Low Power Idle S0 _DSM interface has been discovered and (3) the default sleep state was not selected from the kernel command line. The main motivation for this change is that systems where the (1) and (2) conditions are met typically ship with OSes that don't exercise the S3 path in the platform firmware which remains untested and turns out to be non-functional at least in some cases. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Mario Limonciello <mario.limonciello@dell.com>
Diffstat (limited to 'kernel')
2 files changed, 2 insertions, 3 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 268c1b0afc28..1d2d761e3c25 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -192,7 +192,6 @@ extern void swsusp_show_speed(ktime_t, ktime_t, unsigned int, char *);
extern const char * const pm_labels[];
extern const char *pm_states[];
extern const char *mem_sleep_states[];
-extern suspend_state_t mem_sleep_current;
extern int suspend_devices_and_enter(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4bce46ddc2cd..0639d3a79852 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -48,7 +48,7 @@ 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;
suspend_state_t pm_suspend_target_state;
@@ -216,7 +216,7 @@ 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;