Commit 2a6b6976 authored by Matthew Garrett's avatar Matthew Garrett Committed by Len Brown

ACPI: Store NVS state even when entering suspend to RAM

https://bugzilla.kernel.org/show_bug.cgi?id=13931 describes a bug where
a system fails to successfully resume after the second suspend. Maxim
Levitsky discovered that this could be rectified by forcibly saving
and restoring the ACPI non-volatile state. The spec indicates that this
is only required for S4, but testing the behaviour of Windows by adding
an ACPI NVS region to qemu's e820 map and registering a custom memory
read/write handler reveals that it's saved and restored even over suspend
to RAM. We should mimic that behaviour to avoid other broken platforms.
Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent dd4c4f17
......@@ -112,6 +112,8 @@ static int __acpi_pm_prepare(void)
{
int error = acpi_sleep_prepare(acpi_target_sleep_state);
suspend_nvs_save();
if (error)
acpi_target_sleep_state = ACPI_STATE_S0;
return error;
......@@ -140,6 +142,8 @@ static void acpi_pm_finish(void)
{
u32 acpi_state = acpi_target_sleep_state;
suspend_nvs_free();
if (acpi_state == ACPI_STATE_S0)
return;
......@@ -189,6 +193,11 @@ static int acpi_suspend_begin(suspend_state_t pm_state)
u32 acpi_state = acpi_suspend_states[pm_state];
int error = 0;
error = suspend_nvs_alloc();
if (error)
return error;
if (sleep_states[acpi_state]) {
acpi_target_sleep_state = acpi_state;
acpi_sleep_tts_switch(acpi_target_sleep_state);
......@@ -264,6 +273,8 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
if (acpi_state == ACPI_STATE_S3)
acpi_restore_state_mem();
suspend_nvs_restore();
return ACPI_SUCCESS(status) ? 0 : -EFAULT;
}
......@@ -430,12 +441,6 @@ static int acpi_hibernation_enter(void)
return ACPI_SUCCESS(status) ? 0 : -EFAULT;
}
static void acpi_hibernation_finish(void)
{
suspend_nvs_free();
acpi_pm_finish();
}
static void acpi_hibernation_leave(void)
{
/*
......@@ -473,7 +478,7 @@ static struct platform_hibernation_ops acpi_hibernation_ops = {
.begin = acpi_hibernation_begin,
.end = acpi_pm_end,
.pre_snapshot = acpi_hibernation_pre_snapshot,
.finish = acpi_hibernation_finish,
.finish = acpi_pm_finish,
.prepare = acpi_pm_prepare,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,
......@@ -526,7 +531,7 @@ static struct platform_hibernation_ops acpi_hibernation_ops_old = {
.begin = acpi_hibernation_begin_old,
.end = acpi_pm_end,
.pre_snapshot = acpi_hibernation_pre_snapshot_old,
.finish = acpi_hibernation_finish,
.finish = acpi_pm_finish,
.prepare = acpi_pm_disable_gpes,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,
......
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