ACPI: PM: Call pm_set_suspend_via_firmware() during hibernation

On systems with ACPI platform firmware the last stage of hibernation
is analogous to system suspend to S3 (suspend-to-RAM), so it should
be handled analogously.  In particular, pm_suspend_via_firmware()
should return 'true' in that stage to let the callers of it know that
control will be passed to the platform firmware going forward, so
pm_set_suspend_via_firmware() needs to be called then in analogy with
acpi_suspend_begin().

However, the platform hibernation ->begin() callback is invoked
during the "freeze" transition (before creating a snapshot image of
system memory) as well as during the "hibernate" transition which is
the last stage of it and pm_set_suspend_via_firmware() should be
invoked by that callback in the latter stage only.

In order to implement that redefine the hibernation ->begin()
callback to take a pm_message_t argument to indicate which stage
of hibernation is taking place and rework acpi_hibernation_begin()
and acpi_hibernation_begin_old() to take it into account as needed.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index e52f1238d2d66025b949a51f67b9bb629d3b18a4..a34deccd7317ee6a01350d84c96deecbadc4683e 100644 (file)
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -1132,15 +1132,19 @@ void __init acpi_no_s4_hw_signature(void)
        nosigcheck = true;
 }
 
-static int acpi_hibernation_begin(void)
+static int acpi_hibernation_begin(pm_message_t stage)
 {
-       int error;
+       if (!nvs_nosave) {
+               int error = suspend_nvs_alloc();
+               if (error)
+                       return error;
+       }
 
-       error = nvs_nosave ? 0 : suspend_nvs_alloc();
-       if (!error)
-               acpi_pm_start(ACPI_STATE_S4);
+       if (stage.event == PM_EVENT_HIBERNATE)
+               pm_set_suspend_via_firmware();
 
-       return error;
+       acpi_pm_start(ACPI_STATE_S4);
+       return 0;
 }
 
 static int acpi_hibernation_enter(void)
@@ -1200,7 +1204,7 @@ static const struct platform_hibernation_ops acpi_hibernation_ops = {
  *             function is used if the pre-ACPI 2.0 suspend ordering has been
  *             requested.
  */
-static int acpi_hibernation_begin_old(void)
+static int acpi_hibernation_begin_old(pm_message_t stage)
 {
        int error;
        /*
@@ -1211,16 +1215,21 @@ static int acpi_hibernation_begin_old(void)
        acpi_sleep_tts_switch(ACPI_STATE_S4);
 
        error = acpi_sleep_prepare(ACPI_STATE_S4);
+       if (error)
+               return error;
 
-       if (!error) {
-               if (!nvs_nosave)
-                       error = suspend_nvs_alloc();
-               if (!error) {
-                       acpi_target_sleep_state = ACPI_STATE_S4;
-                       acpi_scan_lock_acquire();
-               }
+       if (!nvs_nosave) {
+               error = suspend_nvs_alloc();
+               if (error)
+                       return error;
        }
-       return error;
+
+       if (stage.event == PM_EVENT_HIBERNATE)
+               pm_set_suspend_via_firmware();
+
+       acpi_target_sleep_state = ACPI_STATE_S4;
+       acpi_scan_lock_acquire();
+       return 0;
 }
 
 /*

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 6b3ea9ea6a9e09e313f28a0df567c3a7a45a1b99..4a2ffd678887f750f848e3289013ac2ede5e9127 100644 (file)
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -359,7 +359,7 @@ extern void mark_free_pages(struct zone *zone);
  *     platforms which require special recovery actions in that situation.
  */
 struct platform_hibernation_ops {
-       int (*begin)(void);
+       int (*begin)(pm_message_t stage);
        void (*end)(void);
        int (*pre_snapshot)(void);
        void (*finish)(void);

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index c8c272df71540656c440fe70e296a4aadf59950c..97522630b1b627dbe7e0a243d9994a7b070db6ed 100644 (file)
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -129,7 +129,7 @@ static int hibernation_test(int level) { return 0; }
 static int platform_begin(int platform_mode)
 {
        return (platform_mode && hibernation_ops) ?
-               hibernation_ops->begin() : 0;
+               hibernation_ops->begin(PMSG_FREEZE) : 0;
 }
 
 /**
@@ -542,7 +542,7 @@ int hibernation_platform_enter(void)
         * hibernation_ops->finish() before saving the image, so we should let
         * the firmware know that we're going to enter the sleep state after all
         */
-       error = hibernation_ops->begin();
+       error = hibernation_ops->begin(PMSG_HIBERNATE);
        if (error)
                goto Close;