1 files changed, 42 insertions, 16 deletions

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 288673cff85e..cfee286ee5c5 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -132,10 +132,10 @@ static bool acpi_nondev_subnode_ok(acpi_handle scope,
 	return acpi_nondev_subnode_data_ok(handle, link, list, parent);
 }
 
-static int acpi_add_nondev_subnodes(acpi_handle scope,
-				    const union acpi_object *links,
-				    struct list_head *list,
-				    struct fwnode_handle *parent)
+static bool acpi_add_nondev_subnodes(acpi_handle scope,
+				     const union acpi_object *links,
+				     struct list_head *list,
+				     struct fwnode_handle *parent)
 {
 	bool ret = false;
 	int i;
@@ -566,6 +566,7 @@ acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
  * @index: Index of the reference to return
  * @num_args: Maximum number of arguments after each reference
  * @args: Location to store the returned reference with optional arguments
+ *	  (may be NULL)
  *
  * Find property with @name, verifify that it is a package containing at least
  * one object reference and if so, store the ACPI device object pointer to the
@@ -618,12 +619,15 @@ int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,
 	 */
 	if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {
 		if (index)
-			return -EINVAL;
+			return -ENOENT;
 
 		ret = acpi_bus_get_device(obj->reference.handle, &device);
 		if (ret)
 			return ret == -ENODEV ? -EINVAL : ret;
 
+		if (!args)
+			return 0;
+
 		args->fwnode = acpi_fwnode_handle(device);
 		args->nargs = 0;
 		return 0;
@@ -720,9 +724,6 @@ static int acpi_data_prop_read_single(const struct acpi_device_data *data,
 	const union acpi_object *obj;
 	int ret;
 
-	if (!val)
-		return -EINVAL;
-
 	if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);
 		if (ret)
@@ -732,28 +733,43 @@ static int acpi_data_prop_read_single(const struct acpi_device_data *data,
 		case DEV_PROP_U8:
 			if (obj->integer.value > U8_MAX)
 				return -EOVERFLOW;
-			*(u8 *)val = obj->integer.value;
+
+			if (val)
+				*(u8 *)val = obj->integer.value;
+
 			break;
 		case DEV_PROP_U16:
 			if (obj->integer.value > U16_MAX)
 				return -EOVERFLOW;
-			*(u16 *)val = obj->integer.value;
+
+			if (val)
+				*(u16 *)val = obj->integer.value;
+
 			break;
 		case DEV_PROP_U32:
 			if (obj->integer.value > U32_MAX)
 				return -EOVERFLOW;
-			*(u32 *)val = obj->integer.value;
+
+			if (val)
+				*(u32 *)val = obj->integer.value;
+
 			break;
 		default:
-			*(u64 *)val = obj->integer.value;
+			if (val)
+				*(u64 *)val = obj->integer.value;
+
 			break;
 		}
+
+		if (!val)
+			return 1;
 	} else if (proptype == DEV_PROP_STRING) {
 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);
 		if (ret)
 			return ret;
 
-		*(char **)val = obj->string.pointer;
+		if (val)
+			*(char **)val = obj->string.pointer;
 
 		return 1;
 	} else {
@@ -767,7 +783,7 @@ int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
 {
 	int ret;
 
-	if (!adev)
+	if (!adev || !val)
 		return -EINVAL;
 
 	ret = acpi_data_prop_read_single(&adev->data, propname, proptype, val);
@@ -861,10 +877,20 @@ static int acpi_data_prop_read(const struct acpi_device_data *data,
 	const union acpi_object *items;
 	int ret;
 
-	if (val && nval == 1) {
+	if (nval == 1 || !val) {
 		ret = acpi_data_prop_read_single(data, propname, proptype, val);
-		if (ret >= 0)
+		/*
+		 * The overflow error means that the property is there and it is
+		 * single-value, but its type does not match, so return.
+		 */
+		if (ret >= 0 || ret == -EOVERFLOW)
 			return ret;
+
+		/*
+		 * Reading this property as a single-value one failed, but its
+		 * value may still be represented as one-element array, so
+		 * continue.
+		 */
 	}
 
 	ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);