Suspend-related patches for 2.6.27

ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering.  Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code.  Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS.  However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 163 insertions, 115 deletions

diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c
index 0f2caea2fc83..4addf8ad50ae 100644
--- a/drivers/acpi/sleep/main.c
+++ b/drivers/acpi/sleep/main.c
@@ -24,10 +24,6 @@
 
 u8 sleep_states[ACPI_S_STATE_COUNT];
 
-#ifdef CONFIG_PM_SLEEP
-static u32 acpi_target_sleep_state = ACPI_STATE_S0;
-#endif
-
 static int acpi_sleep_prepare(u32 acpi_state)
 {
 #ifdef CONFIG_ACPI_SLEEP
@@ -50,9 +46,96 @@ static int acpi_sleep_prepare(u32 acpi_state)
         return 0;
 }
 
-#ifdef CONFIG_SUSPEND
-static struct platform_suspend_ops acpi_suspend_ops;
+#ifdef CONFIG_PM_SLEEP
+static u32 acpi_target_sleep_state = ACPI_STATE_S0;
+
+/*
+ * 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.
+ */
+static bool old_suspend_ordering;
+
+void __init acpi_old_suspend_ordering(void)
+{
+        old_suspend_ordering = true;
+}
+
+/**
+ *      acpi_pm_disable_gpes - Disable the GPEs.
+ */
+static int acpi_pm_disable_gpes(void)
+{
+        acpi_hw_disable_all_gpes();
+        return 0;
+}
+
+/**
+ *      __acpi_pm_prepare - Prepare the platform to enter the target state.
+ *
+ *      If necessary, set the firmware waking vector and do arch-specific
+ *      nastiness to get the wakeup code to the waking vector.
+ */
+static int __acpi_pm_prepare(void)
+{
+        int error = acpi_sleep_prepare(acpi_target_sleep_state);
+
+        if (error)
+                acpi_target_sleep_state = ACPI_STATE_S0;
+        return error;
+}
+
+/**
+ *      acpi_pm_prepare - Prepare the platform to enter the target sleep
+ *              state and disable the GPEs.
+ */
+static int acpi_pm_prepare(void)
+{
+        int error = __acpi_pm_prepare();
+
+        if (!error)
+                acpi_hw_disable_all_gpes();
+        return error;
+}
+
+/**
+ *      acpi_pm_finish - Instruct the platform to leave a sleep state.
+ *
+ *      This is called after we wake back up (or if entering the sleep state
+ *      failed).
+ */
+static void acpi_pm_finish(void)
+{
+        u32 acpi_state = acpi_target_sleep_state;
+
+        if (acpi_state == ACPI_STATE_S0)
+                return;
 
+        printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
+                acpi_state);
+        acpi_disable_wakeup_device(acpi_state);
+        acpi_leave_sleep_state(acpi_state);
+
+        /* reset firmware waking vector */
+        acpi_set_firmware_waking_vector((acpi_physical_address) 0);
+
+        acpi_target_sleep_state = ACPI_STATE_S0;
+}
+
+/**
+ *      acpi_pm_end - Finish up suspend sequence.
+ */
+static void acpi_pm_end(void)
+{
+        /*
+         * This is necessary in case acpi_pm_finish() is not called during a
+         * failing transition to a sleep state.
+         */
+        acpi_target_sleep_state = ACPI_STATE_S0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_SUSPEND
 extern void do_suspend_lowlevel(void);
 
 static u32 acpi_suspend_states[] = {
@@ -66,7 +149,6 @@ static u32 acpi_suspend_states[] = {
  *      acpi_suspend_begin - Set the target system sleep state to the state
  *              associated with given @pm_state, if supported.
  */
-
 static int acpi_suspend_begin(suspend_state_t pm_state)
 {
         u32 acpi_state = acpi_suspend_states[pm_state];
@@ -83,25 +165,6 @@ static int acpi_suspend_begin(suspend_state_t pm_state)
 }
 
 /**
- *      acpi_suspend_prepare - Do preliminary suspend work.
- *
- *      If necessary, set the firmware waking vector and do arch-specific
- *      nastiness to get the wakeup code to the waking vector.
- */
-
-static int acpi_suspend_prepare(void)
-{
-        int error = acpi_sleep_prepare(acpi_target_sleep_state);
-
-        if (error) {
-                acpi_target_sleep_state = ACPI_STATE_S0;
-                return error;
-        }
-
-        return ACPI_SUCCESS(acpi_hw_disable_all_gpes()) ? 0 : -EFAULT;
-}
-
-/**
  *      acpi_suspend_enter - Actually enter a sleep state.
  *      @pm_state: ignored
  *
@@ -109,7 +172,6 @@ static int acpi_suspend_prepare(void)
  *      assembly, which in turn call acpi_enter_sleep_state().
  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
  */
-
 static int acpi_suspend_enter(suspend_state_t pm_state)
 {
         acpi_status status = AE_OK;
@@ -166,39 +228,6 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 }
 
-/**
- *      acpi_suspend_finish - Instruct the platform to leave a sleep state.
- *
- *      This is called after we wake back up (or if entering the sleep state
- *      failed). 
- */
-
-static void acpi_suspend_finish(void)
-{
-        u32 acpi_state = acpi_target_sleep_state;
-
-        acpi_disable_wakeup_device(acpi_state);
-        acpi_leave_sleep_state(acpi_state);
-
-        /* reset firmware waking vector */
-        acpi_set_firmware_waking_vector((acpi_physical_address) 0);
-
-        acpi_target_sleep_state = ACPI_STATE_S0;
-}
-
-/**
- *      acpi_suspend_end - Finish up suspend sequence.
- */
-
-static void acpi_suspend_end(void)
-{
-        /*
-         * This is necessary in case acpi_suspend_finish() is not called during a
-         * failing transition to a sleep state.
-         */
-        acpi_target_sleep_state = ACPI_STATE_S0;
-}
-
 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 {
         u32 acpi_state;
@@ -218,10 +247,39 @@ static int acpi_suspend_state_valid(suspend_state_t pm_state)
 static struct platform_suspend_ops acpi_suspend_ops = {
         .valid = acpi_suspend_state_valid,
         .begin = acpi_suspend_begin,
-        .prepare = acpi_suspend_prepare,
+        .prepare = acpi_pm_prepare,
+        .enter = acpi_suspend_enter,
+        .finish = acpi_pm_finish,
+        .end = acpi_pm_end,
+};
+
+/**
+ *      acpi_suspend_begin_old - Set the target system sleep state to the
+ *              state associated with given @pm_state, if supported, and
+ *              execute the _PTS control method.  This function is used if the
+ *              pre-ACPI 2.0 suspend ordering has been requested.
+ */
+static int acpi_suspend_begin_old(suspend_state_t pm_state)
+{
+        int error = acpi_suspend_begin(pm_state);
+
+        if (!error)
+                error = __acpi_pm_prepare();
+        return error;
+}
+
+/*
+ * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
+ * been requested.
+ */
+static struct platform_suspend_ops acpi_suspend_ops_old = {
+        .valid = acpi_suspend_state_valid,
+        .begin = acpi_suspend_begin_old,
+        .prepare = acpi_pm_disable_gpes,
         .enter = acpi_suspend_enter,
-        .finish = acpi_suspend_finish,
-        .end = acpi_suspend_end,
+        .finish = acpi_pm_finish,
+        .end = acpi_pm_end,
+        .recover = acpi_pm_finish,
 };
 #endif /* CONFIG_SUSPEND */
 
@@ -229,22 +287,9 @@ static struct platform_suspend_ops acpi_suspend_ops = {
 static int acpi_hibernation_begin(void)
 {
         acpi_target_sleep_state = ACPI_STATE_S4;
-
         return 0;
 }
 
-static int acpi_hibernation_prepare(void)
-{
-        int error = acpi_sleep_prepare(ACPI_STATE_S4);
-
-        if (error) {
-                acpi_target_sleep_state = ACPI_STATE_S0;
-                return error;
-        }
-
-        return ACPI_SUCCESS(acpi_hw_disable_all_gpes()) ? 0 : -EFAULT;
-}
-
 static int acpi_hibernation_enter(void)
 {
         acpi_status status = AE_OK;
@@ -274,52 +319,55 @@ static void acpi_hibernation_leave(void)
         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 }
 
-static void acpi_hibernation_finish(void)
+static void acpi_pm_enable_gpes(void)
 {
-        acpi_disable_wakeup_device(ACPI_STATE_S4);
-        acpi_leave_sleep_state(ACPI_STATE_S4);
-
-        /* reset firmware waking vector */
-        acpi_set_firmware_waking_vector((acpi_physical_address) 0);
-
-        acpi_target_sleep_state = ACPI_STATE_S0;
+        acpi_hw_enable_all_runtime_gpes();
 }
 
-static void acpi_hibernation_end(void)
-{
-        /*
-         * This is necessary in case acpi_hibernation_finish() is not called
-         * during a failing transition to the sleep state.
-         */
-        acpi_target_sleep_state = ACPI_STATE_S0;
-}
+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,
+        .prepare = acpi_pm_prepare,
+        .enter = acpi_hibernation_enter,
+        .leave = acpi_hibernation_leave,
+        .pre_restore = acpi_pm_disable_gpes,
+        .restore_cleanup = acpi_pm_enable_gpes,
+};
 
-static int acpi_hibernation_pre_restore(void)
+/**
+ *      acpi_hibernation_begin_old - Set the target system sleep state to
+ *              ACPI_STATE_S4 and execute the _PTS control method.  This
+ *              function is used if the pre-ACPI 2.0 suspend ordering has been
+ *              requested.
+ */
+static int acpi_hibernation_begin_old(void)
 {
-        acpi_status status;
-
-        status = acpi_hw_disable_all_gpes();
-
-        return ACPI_SUCCESS(status) ? 0 : -EFAULT;
-}
+        int error = acpi_sleep_prepare(ACPI_STATE_S4);
 
-static void acpi_hibernation_restore_cleanup(void)
-{
-        acpi_hw_enable_all_runtime_gpes();
+        if (!error)
+                acpi_target_sleep_state = ACPI_STATE_S4;
+        return error;
 }
 
-static struct platform_hibernation_ops acpi_hibernation_ops = {
-        .begin = acpi_hibernation_begin,
-        .end = acpi_hibernation_end,
-        .pre_snapshot = acpi_hibernation_prepare,
-        .finish = acpi_hibernation_finish,
-        .prepare = acpi_hibernation_prepare,
+/*
+ * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
+ * been requested.
+ */
+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,
+        .prepare = acpi_pm_disable_gpes,
         .enter = acpi_hibernation_enter,
         .leave = acpi_hibernation_leave,
-        .pre_restore = acpi_hibernation_pre_restore,
-        .restore_cleanup = acpi_hibernation_restore_cleanup,
+        .pre_restore = acpi_pm_disable_gpes,
+        .restore_cleanup = acpi_pm_enable_gpes,
+        .recover = acpi_pm_finish,
 };
-#endif                          /* CONFIG_HIBERNATION */
+#endif /* CONFIG_HIBERNATION */
 
 int acpi_suspend(u32 acpi_state)
 {
@@ -461,13 +509,15 @@ int __init acpi_sleep_init(void)
                 }
         }
 
-        suspend_set_ops(&acpi_suspend_ops);
+        suspend_set_ops(old_suspend_ordering ?
+                &acpi_suspend_ops_old : &acpi_suspend_ops);
 #endif
 
 #ifdef CONFIG_HIBERNATION
         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
         if (ACPI_SUCCESS(status)) {
-                hibernation_set_ops(&acpi_hibernation_ops);
+                hibernation_set_ops(old_suspend_ordering ?
+                        &acpi_hibernation_ops_old : &acpi_hibernation_ops);
                 sleep_states[ACPI_STATE_S4] = 1;
                 printk(" S4");
         }
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index d571204aaff7..3250c5257b74 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -781,8 +781,6 @@ int device_suspend(pm_message_t state)
         error = dpm_prepare(state);
         if (!error)
                 error = dpm_suspend(state);
-        if (error)
-                device_resume(resume_event(state));
         return error;
 }
 EXPORT_SYMBOL_GPL(device_suspend);