ACPI / PM: Take order attribute of power resources into account

ACPI power resources have an order attribute that should be taken
into account when turning them on and off, but it is not used now.

Modify the power resources management code to preserve the
spec-compliant ordering of power resources that power states of
devices depend on (analogous changes will be done separately for
power resources used for wakeup).

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

1 files changed, 26 insertions, 5 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c7ea9c2649a4..d557868c0081 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -475,11 +475,25 @@ void acpi_free_ids(struct acpi_device *device)
         kfree(device->pnp.unique_id);
 }
 
+static void acpi_free_power_resources_lists(struct acpi_device *device)
+{
+        int i;
+
+        if (!device->flags.power_manageable)
+                return;
+
+        for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
+                struct acpi_device_power_state *ps = &device->power.states[i];
+                acpi_power_resources_list_free(&ps->resources);
+        }
+}
+
 static void acpi_device_release(struct device *dev)
 {
         struct acpi_device *acpi_dev = to_acpi_device(dev);
 
         acpi_free_ids(acpi_dev);
+        acpi_free_power_resources_lists(acpi_dev);
         kfree(acpi_dev);
 }
 
@@ -1055,17 +1069,22 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
                 struct acpi_device_power_state *ps = &device->power.states[i];
                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
+                struct acpi_handle_list resources;
 
+                INIT_LIST_HEAD(&ps->resources);
                 /* Evaluate "_PRx" to se if power resources are referenced */
                 acpi_evaluate_reference(device->handle, object_name, NULL,
-                                        &ps->resources);
-                if (ps->resources.count) {
+                                        &resources);
+                if (resources.count) {
                         int j;
 
                         device->power.flags.power_resources = 1;
-                        for (j = 0; j < ps->resources.count; j++) {
-                                acpi_handle rhandle = ps->resources.handles[j];
+                        for (j = 0; j < resources.count; j++) {
+                                acpi_handle rhandle = resources.handles[j];
+
                                 acpi_add_power_resource(rhandle);
+                                acpi_power_resources_list_add(rhandle,
+                                                              &ps->resources);
                         }
                 }
 
@@ -1079,7 +1098,7 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
                  * State is valid if there are means to put the device into it.
                  * D3hot is only valid if _PR3 present.
                  */
-                if (ps->resources.count ||
+                if (resources.count ||
                     (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT)) {
                         ps->flags.valid = 1;
                         ps->flags.os_accessible = 1;
@@ -1089,6 +1108,8 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
                 ps->latency = -1;       /* Unknown - driver assigned */
         }
 
+        INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
+
         /* Set defaults for D0 and D3 states (always valid) */
         device->power.states[ACPI_STATE_D0].flags.valid = 1;
         device->power.states[ACPI_STATE_D0].power = 100;