Merge branch 'acpi-pm'

* acpi-pm:
  ACPI / PM: Expose lists of device wakeup power resources to user space
  ACPI / PM: Fix potential problem in acpi_device_get_power()

3 files changed, 76 insertions, 34 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_wakeup b/Documentation/ABI/testing/sysfs-devices-power_resources_wakeup
new file mode 100644
index 000000000000..e0588feeb6e1
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-power_resources_wakeup
@@ -0,0 +1,13 @@
+What:           /sys/devices/.../power_resources_wakeup/
+Date:           April 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                The /sys/devices/.../power_resources_wakeup/ directory is only
+                present for device objects representing ACPI device nodes that
+                require ACPI power resources for wakeup signaling.
+
+                If present, it contains symbolic links to device directories
+                representing ACPI power resources that need to be turned on for
+                the given device node to be able to signal wakeup.  The names of
+                the links are the same as the names of the directories they
+                point to.
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index dd314ef9bff1..96de787e6104 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -145,27 +145,36 @@ int acpi_device_get_power(struct acpi_device *device, int *state)
         }
 
         /*
-         * Get the device's power state either directly (via _PSC) or
-         * indirectly (via power resources).
+         * Get the device's power state from power resources settings and _PSC,
+         * if available.
          */
+        if (device->power.flags.power_resources) {
+                int error = acpi_power_get_inferred_state(device, &result);
+                if (error)
+                        return error;
+        }
         if (device->power.flags.explicit_get) {
+                acpi_handle handle = device->handle;
                 unsigned long long psc;
-                acpi_status status = acpi_evaluate_integer(device->handle,
-                                                           "_PSC", NULL, &psc);
+                acpi_status status;
+
+                status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
                 if (ACPI_FAILURE(status))
                         return -ENODEV;
 
-                result = psc;
-        }
-        /* The test below covers ACPI_STATE_UNKNOWN too. */
-        if (result <= ACPI_STATE_D2) {
-          ; /* Do nothing. */
-        } else if (device->power.flags.power_resources) {
-                int error = acpi_power_get_inferred_state(device, &result);
-                if (error)
-                        return error;
-        } else if (result == ACPI_STATE_D3_HOT) {
-                result = ACPI_STATE_D3;
+                /*
+                 * The power resources settings may indicate a power state
+                 * shallower than the actual power state of the device.
+                 *
+                 * Moreover, on systems predating ACPI 4.0, if the device
+                 * doesn't depend on any power resources and _PSC returns 3,
+                 * that means "power off".  We need to maintain compatibility
+                 * with those systems.
+                 */
+                if (psc > result && psc < ACPI_STATE_D3_COLD)
+                        result = psc;
+                else if (result == ACPI_STATE_UNKNOWN)
+                        result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc;
         }
 
         /*
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 0481b1b1d2aa..f962047c6c85 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -459,57 +459,79 @@ static struct attribute_group attr_groups[] = {
         },
 };
 
-static void acpi_power_hide_list(struct acpi_device *adev, int state)
+static struct attribute_group wakeup_attr_group = {
+        .name = "power_resources_wakeup",
+        .attrs = attrs,
+};
+
+static void acpi_power_hide_list(struct acpi_device *adev,
+                                 struct list_head *resources,
+                                 struct attribute_group *attr_group)
 {
-        struct acpi_device_power_state *ps = &adev->power.states[state];
         struct acpi_power_resource_entry *entry;
 
-        if (list_empty(&ps->resources))
+        if (list_empty(resources))
                 return;
 
-        list_for_each_entry_reverse(entry, &ps->resources, node) {
+        list_for_each_entry_reverse(entry, resources, node) {
                 struct acpi_device *res_dev = &entry->resource->device;
 
                 sysfs_remove_link_from_group(&adev->dev.kobj,
-                                             attr_groups[state].name,
+                                             attr_group->name,
                                              dev_name(&res_dev->dev));
         }
-        sysfs_remove_group(&adev->dev.kobj, &attr_groups[state]);
+        sysfs_remove_group(&adev->dev.kobj, attr_group);
 }
 
-static void acpi_power_expose_list(struct acpi_device *adev, int state)
+static void acpi_power_expose_list(struct acpi_device *adev,
+                                   struct list_head *resources,
+                                   struct attribute_group *attr_group)
 {
-        struct acpi_device_power_state *ps = &adev->power.states[state];
         struct acpi_power_resource_entry *entry;
         int ret;
 
-        if (list_empty(&ps->resources))
+        if (list_empty(resources))
                 return;
 
-        ret = sysfs_create_group(&adev->dev.kobj, &attr_groups[state]);
+        ret = sysfs_create_group(&adev->dev.kobj, attr_group);
         if (ret)
                 return;
 
-        list_for_each_entry(entry, &ps->resources, node) {
+        list_for_each_entry(entry, resources, node) {
                 struct acpi_device *res_dev = &entry->resource->device;
 
                 ret = sysfs_add_link_to_group(&adev->dev.kobj,
-                                              attr_groups[state].name,
+                                              attr_group->name,
                                               &res_dev->dev.kobj,
                                               dev_name(&res_dev->dev));
                 if (ret) {
-                        acpi_power_hide_list(adev, state);
+                        acpi_power_hide_list(adev, resources, attr_group);
                         break;
                 }
         }
 }
 
+static void acpi_power_expose_hide(struct acpi_device *adev,
+                                   struct list_head *resources,
+                                   struct attribute_group *attr_group,
+                                   bool expose)
+{
+        if (expose)
+                acpi_power_expose_list(adev, resources, attr_group);
+        else
+                acpi_power_hide_list(adev, resources, attr_group);
+}
+
 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 {
         struct acpi_device_power_state *ps;
         struct acpi_power_resource_entry *entry;
         int state;
 
+        if (adev->wakeup.flags.valid)
+                acpi_power_expose_hide(adev, &adev->wakeup.resources,
+                                       &wakeup_attr_group, add);
+
         if (!adev->power.flags.power_resources)
                 return;
 
@@ -523,12 +545,10 @@ void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
                         acpi_power_remove_dependent(resource, adev);
         }
 
-        for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++) {
-                if (add)
-                        acpi_power_expose_list(adev, state);
-                else
-                        acpi_power_hide_list(adev, state);
-        }
+        for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
+                acpi_power_expose_hide(adev,
+                                       &adev->power.states[state].resources,
+                                       &attr_groups[state], add);
 }
 
 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)