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-rw-r--r--arch/x86/kernel/acpi/sleep.c2
-rw-r--r--drivers/acpi/sleep.c17
-rw-r--r--include/linux/acpi.h1
3 files changed, 19 insertions, 1 deletions
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 11676cf65aee..d5e0d717005a 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -101,6 +101,8 @@ static int __init acpi_sleep_setup(char *str)
#endif
if (strncmp(str, "nonvs", 5) == 0)
acpi_nvs_nosave();
+ if (strncmp(str, "nonvs_s3", 8) == 0)
+ acpi_nvs_nosave_s3();
if (strncmp(str, "old_ordering", 12) == 0)
acpi_old_suspend_ordering();
str = strchr(str, ',');
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index fdcdbb652915..8640782944cc 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -98,6 +98,21 @@ void __init acpi_nvs_nosave(void)
}
/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * but says nothing about saving NVS during S3. Not all versions of Windows
+ * save NVS on S3 suspend either, and it is clear that not all systems need
+ * NVS to be saved at S3 time. To improve suspend/resume time, allow the
+ * user to disable saving NVS on S3 if their system does not require it, but
+ * continue to save/restore NVS for S4 as specified.
+ */
+static bool nvs_nosave_s3;
+
+void __init acpi_nvs_nosave_s3(void)
+{
+ nvs_nosave_s3 = true;
+}
+
+/*
* ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
* user to request that behavior by using the 'acpi_old_suspend_ordering'
* kernel command line option that causes the following variable to be set.
@@ -243,7 +258,7 @@ static int acpi_suspend_begin(suspend_state_t pm_state)
u32 acpi_state = acpi_suspend_states[pm_state];
int error = 0;
- error = nvs_nosave ? 0 : suspend_nvs_alloc();
+ error = (nvs_nosave || nvs_nosave_s3) ? 0 : suspend_nvs_alloc();
if (error)
return error;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 90be98981102..3cf93491125c 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -261,6 +261,7 @@ int acpi_resources_are_enforced(void);
void __init acpi_no_s4_hw_signature(void);
void __init acpi_old_suspend_ordering(void);
void __init acpi_nvs_nosave(void);
+void __init acpi_nvs_nosave_s3(void);
#endif /* CONFIG_PM_SLEEP */
struct acpi_osc_context {
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