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path: root/drivers/acpi/main.c
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Diffstat (limited to 'drivers/acpi/main.c')
-rw-r--r--drivers/acpi/main.c67
1 files changed, 59 insertions, 8 deletions
diff --git a/drivers/acpi/main.c b/drivers/acpi/main.c
index d8242772de9..7e3c609cbef 100644
--- a/drivers/acpi/main.c
+++ b/drivers/acpi/main.c
@@ -101,6 +101,19 @@ void __init acpi_old_suspend_ordering(void)
* cases.
*/
static bool set_sci_en_on_resume;
+/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * and to restore them during the subsequent resume. However, it is not certain
+ * if this mechanism is going to work on all machines, so we allow the user to
+ * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
+ * option.
+ */
+static bool s4_no_nvs;
+
+void __init acpi_s4_no_nvs(void)
+{
+ s4_no_nvs = true;
+}
/**
* acpi_pm_disable_gpes - Disable the GPEs.
@@ -394,9 +407,25 @@ void __init acpi_no_s4_hw_signature(void)
static int acpi_hibernation_begin(void)
{
- acpi_target_sleep_state = ACPI_STATE_S4;
- acpi_sleep_tts_switch(acpi_target_sleep_state);
- return 0;
+ int error;
+
+ error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
+ if (!error) {
+ acpi_target_sleep_state = ACPI_STATE_S4;
+ acpi_sleep_tts_switch(acpi_target_sleep_state);
+ }
+
+ return error;
+}
+
+static int acpi_hibernation_pre_snapshot(void)
+{
+ int error = acpi_pm_prepare();
+
+ if (!error)
+ hibernate_nvs_save();
+
+ return error;
}
static int acpi_hibernation_enter(void)
@@ -417,6 +446,12 @@ static int acpi_hibernation_enter(void)
return ACPI_SUCCESS(status) ? 0 : -EFAULT;
}
+static void acpi_hibernation_finish(void)
+{
+ hibernate_nvs_free();
+ acpi_pm_finish();
+}
+
static void acpi_hibernation_leave(void)
{
/*
@@ -432,6 +467,8 @@ static void acpi_hibernation_leave(void)
"cannot resume!\n");
panic("ACPI S4 hardware signature mismatch");
}
+ /* Restore the NVS memory area */
+ hibernate_nvs_restore();
}
static void acpi_pm_enable_gpes(void)
@@ -442,8 +479,8 @@ static void acpi_pm_enable_gpes(void)
static struct platform_hibernation_ops acpi_hibernation_ops = {
.begin = acpi_hibernation_begin,
.end = acpi_pm_end,
- .pre_snapshot = acpi_pm_prepare,
- .finish = acpi_pm_finish,
+ .pre_snapshot = acpi_hibernation_pre_snapshot,
+ .finish = acpi_hibernation_finish,
.prepare = acpi_pm_prepare,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,
@@ -469,8 +506,22 @@ static int acpi_hibernation_begin_old(void)
error = acpi_sleep_prepare(ACPI_STATE_S4);
+ if (!error) {
+ if (!s4_no_nvs)
+ error = hibernate_nvs_alloc();
+ if (!error)
+ acpi_target_sleep_state = ACPI_STATE_S4;
+ }
+ return error;
+}
+
+static int acpi_hibernation_pre_snapshot_old(void)
+{
+ int error = acpi_pm_disable_gpes();
+
if (!error)
- acpi_target_sleep_state = ACPI_STATE_S4;
+ hibernate_nvs_save();
+
return error;
}
@@ -481,8 +532,8 @@ static int acpi_hibernation_begin_old(void)
static struct platform_hibernation_ops acpi_hibernation_ops_old = {
.begin = acpi_hibernation_begin_old,
.end = acpi_pm_end,
- .pre_snapshot = acpi_pm_disable_gpes,
- .finish = acpi_pm_finish,
+ .pre_snapshot = acpi_hibernation_pre_snapshot_old,
+ .finish = acpi_hibernation_finish,
.prepare = acpi_pm_disable_gpes,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,