Merge branch 'device-properties'

* device-properties:
  ACPI / property: Document usage rules for _DSD properties
  ACPI / property: Hierarchical properties support update

2 files changed, 93 insertions, 40 deletions

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 7b2c48fde4e2..24418932612e 100644
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -52,7 +52,7 @@ struct acpi_data_node_attr {
 
 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
 {
-        return acpi_object_path(dn->handle, buf);
+        return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
 }
 
 DATA_NODE_ATTR(path);
@@ -105,10 +105,10 @@ static void acpi_expose_nondev_subnodes(struct kobject *kobj,
                 init_completion(&dn->kobj_done);
                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
                                            kobj, "%s", dn->name);
-                if (ret)
-                        acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
-                else
+                if (!ret)
                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
+                else if (dn->handle)
+                        acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
         }
 }
 
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 03f5ec11ab31..3afddcd834ef 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -41,14 +41,13 @@ static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
 static bool acpi_extract_properties(const union acpi_object *desc,
                                     struct acpi_device_data *data);
 
-static bool acpi_nondev_subnode_ok(acpi_handle scope,
-                                   const union acpi_object *link,
-                                   struct list_head *list)
+static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
+                                        acpi_handle handle,
+                                        const union acpi_object *link,
+                                        struct list_head *list)
 {
-        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
         struct acpi_data_node *dn;
-        acpi_handle handle;
-        acpi_status status;
+        bool result;
 
         dn = kzalloc(sizeof(*dn), GFP_KERNEL);
         if (!dn)
@@ -58,43 +57,75 @@ static bool acpi_nondev_subnode_ok(acpi_handle scope,
         dn->fwnode.type = FWNODE_ACPI_DATA;
         INIT_LIST_HEAD(&dn->data.subnodes);
 
-        status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
-                                 &handle);
-        if (ACPI_FAILURE(status))
-                goto fail;
+        result = acpi_extract_properties(desc, &dn->data);
 
-        status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
-                                            ACPI_TYPE_PACKAGE);
-        if (ACPI_FAILURE(status))
-                goto fail;
+        if (handle) {
+                acpi_handle scope;
+                acpi_status status;
 
-        if (acpi_extract_properties(buf.pointer, &dn->data))
-                dn->handle = handle;
+                /*
+                 * The scope for the subnode object lookup is the one of the
+                 * namespace node (device) containing the object that has
+                 * returned the package.  That is, it's the scope of that
+                 * object's parent.
+                 */
+                status = acpi_get_parent(handle, &scope);
+                if (ACPI_SUCCESS(status)
+                    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data))
+                        result = true;
+        } else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data)) {
+                result = true;
+        }
 
-        /*
-         * The scope for the subnode object lookup is the one of the namespace
-         * node (device) containing the object that has returned the package.
-         * That is, it's the scope of that object's parent.
-         */
-        status = acpi_get_parent(handle, &scope);
-        if (ACPI_SUCCESS(status)
-            && acpi_enumerate_nondev_subnodes(scope, buf.pointer, &dn->data))
+        if (result) {
                 dn->handle = handle;
-
-        if (dn->handle) {
-                dn->data.pointer = buf.pointer;
+                dn->data.pointer = desc;
                 list_add_tail(&dn->sibling, list);
                 return true;
         }
 
+        kfree(dn);
         acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
+        return false;
+}
+
+static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
+                                        const union acpi_object *link,
+                                        struct list_head *list)
+{
+        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+        acpi_status status;
+
+        status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
+                                            ACPI_TYPE_PACKAGE);
+        if (ACPI_FAILURE(status))
+                return false;
+
+        if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list))
+                return true;
 
- fail:
         ACPI_FREE(buf.pointer);
-        kfree(dn);
         return false;
 }
 
+static bool acpi_nondev_subnode_ok(acpi_handle scope,
+                                   const union acpi_object *link,
+                                   struct list_head *list)
+{
+        acpi_handle handle;
+        acpi_status status;
+
+        if (!scope)
+                return false;
+
+        status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
+                                 &handle);
+        if (ACPI_FAILURE(status))
+                return false;
+
+        return acpi_nondev_subnode_data_ok(handle, link, list);
+}
+
 static int acpi_add_nondev_subnodes(acpi_handle scope,
                                     const union acpi_object *links,
                                     struct list_head *list)
@@ -103,15 +134,37 @@ static int acpi_add_nondev_subnodes(acpi_handle scope,
         int i;
 
         for (i = 0; i < links->package.count; i++) {
-                const union acpi_object *link;
+                const union acpi_object *link, *desc;
+                acpi_handle handle;
+                bool result;
 
                 link = &links->package.elements[i];
-                /* Only two elements allowed, both must be strings. */
-                if (link->package.count == 2
-                    && link->package.elements[0].type == ACPI_TYPE_STRING
-                    && link->package.elements[1].type == ACPI_TYPE_STRING
-                    && acpi_nondev_subnode_ok(scope, link, list))
-                        ret = true;
+                /* Only two elements allowed. */
+                if (link->package.count != 2)
+                        continue;
+
+                /* The first one must be a string. */
+                if (link->package.elements[0].type != ACPI_TYPE_STRING)
+                        continue;
+
+                /* The second one may be a string, a reference or a package. */
+                switch (link->package.elements[1].type) {
+                case ACPI_TYPE_STRING:
+                        result = acpi_nondev_subnode_ok(scope, link, list);
+                        break;
+                case ACPI_TYPE_LOCAL_REFERENCE:
+                        handle = link->package.elements[1].reference.handle;
+                        result = acpi_nondev_subnode_data_ok(handle, link, list);
+                        break;
+                case ACPI_TYPE_PACKAGE:
+                        desc = &link->package.elements[1];
+                        result = acpi_nondev_subnode_extract(desc, NULL, link, list);
+                        break;
+                default:
+                        result = false;
+                        break;
+                }
+                ret = ret || result;
         }
 
         return ret;