ACPI / PM: Avoid resuming devices in ACPI PM domain during system suspend

Rework the ACPI PM domain's PM callbacks to avoid resuming devices
during system suspend (in order to modify their wakeup settings etc.)
if that isn't necessary.

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

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index d047739f3380f2d0e53304002499205abe08abd1..9e5fd9c440b7525e7bf65119c8d9783c9803ac45 100644 (file)
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -900,17 +900,45 @@ EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
  */
 int acpi_subsys_prepare(struct device *dev)
 {
-       /*
-        * Devices having power.ignore_children set may still be necessary for
-        * suspending their children in the next phase of device suspend.
-        */
-       if (dev->power.ignore_children)
-               pm_runtime_resume(dev);
+       struct acpi_device *adev = ACPI_COMPANION(dev);
+       u32 sys_target;
+       int ret, state;
+
+       ret = pm_generic_prepare(dev);
+       if (ret < 0)
+               return ret;
+
+       if (!adev || !pm_runtime_suspended(dev)
+           || device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
+               return 0;
+
+       sys_target = acpi_target_system_state();
+       if (sys_target == ACPI_STATE_S0)
+               return 1;
 
-       return pm_generic_prepare(dev);
+       if (adev->power.flags.dsw_present)
+               return 0;
+
+       ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
+       return !ret && state == adev->power.state;
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
 
+/**
+ * acpi_subsys_complete - Finalize device's resume during system resume.
+ * @dev: Device to handle.
+ */
+static void acpi_subsys_complete(struct device *dev)
+{
+       /*
+        * If the device had been runtime-suspended before the system went into
+        * the sleep state it is going out of and it has never been resumed till
+        * now, resume it in case the firmware powered it up.
+        */
+       if (dev->power.direct_complete)
+               pm_request_resume(dev);
+}
+
 /**
  * acpi_subsys_suspend - Run the device driver's suspend callback.
  * @dev: Device to handle.
@@ -979,6 +1007,7 @@ static struct dev_pm_domain acpi_general_pm_domain = {
 #endif
 #ifdef CONFIG_PM_SLEEP
                .prepare = acpi_subsys_prepare,
+               .complete = acpi_subsys_complete,
                .suspend = acpi_subsys_suspend,
                .suspend_late = acpi_subsys_suspend_late,
                .resume_early = acpi_subsys_resume_early,

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7efe546a8c42704137f3cbae8a3159485f3473b9..df6e4c924b353a24db62d5b222572135f0240816 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1551,9 +1551,13 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
         */
        if (acpi_has_method(device->handle, "_PSC"))
                device->power.flags.explicit_get = 1;
+
        if (acpi_has_method(device->handle, "_IRC"))
                device->power.flags.inrush_current = 1;
 
+       if (acpi_has_method(device->handle, "_DSW"))
+               device->power.flags.dsw_present = 1;
+
        /*
         * Enumerate supported power management states
         */

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 84a2e29a231409701de1a9d579a1a139cccbd40c..7417a16c8d86a94ea1d64101e020dba006a681c1 100644 (file)
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -261,7 +261,8 @@ struct acpi_device_power_flags {
        u32 inrush_current:1;   /* Serialize Dx->D0 */
        u32 power_removed:1;    /* Optimize Dx->D0 */
        u32 ignore_parent:1;    /* Power is independent of parent power state */
-       u32 reserved:27;
+       u32 dsw_present:1;      /* _DSW present? */
+       u32 reserved:26;
 };
 
 struct acpi_device_power_state {