1 files changed, 33 insertions, 11 deletions

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 7a3194e2e090..da39117032df 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -688,9 +688,6 @@ 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)
@@ -700,28 +697,43 @@ 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 {
@@ -735,7 +747,7 @@ 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);
@@ -829,10 +841,20 @@ 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);