From 2a6b69765ad794389f2fc3e14a0afa1a995221c2 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Fri, 28 May 2010 16:32:15 -0400 Subject: [PATCH] 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: Matthew Garrett Signed-off-by: Len Brown --- drivers/acpi/sleep.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index bcaa6ef..403daf0 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -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, -- 2.7.4