platform/x86: sony-laptop: SNC calls should handle BUFFER types

After commit 6d232b29 ("ACPICA: Dispatcher: always generate buffer
objects for ASL create_field() operator") ACPICA creates buffers even
when new fields are small enough to fit into an integer.
Many SNC calls counted on the old behaviour.
Since sony-laptop already handles the INTEGER/BUFFER case in
sony_nc_buffer_call, switch sony_nc_int_call to use its more generic
function instead.

Fixes: 6d232b29 ("ACPICA: Dispatcher: always generate buffer objects for ASL create_field() operator")
Reported-by: Dominik Mierzejewski <dominik@greysector.net>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207491Reported-by: William Bader <williambader@hotmail.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1830150Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/sony-laptop.c

@@ -757,33 +757,6 @@ static union acpi_object *__call_snc_method(acpi_handle handle, char *method,
 	return result;
 }
 
-static int sony_nc_int_call(acpi_handle handle, char *name, int *value,
-		int *result)
-{
-	union acpi_object *object = NULL;
-	if (value) {
-		u64 v = *value;
-		object = __call_snc_method(handle, name, &v);
-	} else
-		object = __call_snc_method(handle, name, NULL);
-
-	if (!object)
-		return -EINVAL;
-
-	if (object->type != ACPI_TYPE_INTEGER) {
-		pr_warn("Invalid acpi_object: expected 0x%x got 0x%x\n",
-				ACPI_TYPE_INTEGER, object->type);
-		kfree(object);
-		return -EINVAL;
-	}
-
-	if (result)
-		*result = object->integer.value;
-
-	kfree(object);
-	return 0;
-}
-
 #define MIN(a, b)	(a > b ? b : a)
 static int sony_nc_buffer_call(acpi_handle handle, char *name, u64 *value,
 		void *buffer, size_t buflen)
@@ -795,17 +768,20 @@ static int sony_nc_buffer_call(acpi_handle handle, char *name, u64 *value,
 	if (!object)
 		return -EINVAL;
 
-	if (object->type == ACPI_TYPE_BUFFER) {
+	if (!buffer) {
+		/* do nothing */
+	} else if (object->type == ACPI_TYPE_BUFFER) {
 		len = MIN(buflen, object->buffer.length);
+		memset(buffer, 0, buflen);
 		memcpy(buffer, object->buffer.pointer, len);
 
 	} else if (object->type == ACPI_TYPE_INTEGER) {
 		len = MIN(buflen, sizeof(object->integer.value));
+		memset(buffer, 0, buflen);
 		memcpy(buffer, &object->integer.value, len);
 
 	} else {
-		pr_warn("Invalid acpi_object: expected 0x%x got 0x%x\n",
-				ACPI_TYPE_BUFFER, object->type);
+		pr_warn("Unexpected acpi_object: 0x%x\n", object->type);
 		ret = -EINVAL;
 	}
 
@@ -813,6 +789,23 @@ static int sony_nc_buffer_call(acpi_handle handle, char *name, u64 *value,
 	return ret;
 }
 
+static int sony_nc_int_call(acpi_handle handle, char *name, int *value, int
+		*result)
+{
+	int ret;
+
+	if (value) {
+		u64 v = *value;
+
+		ret = sony_nc_buffer_call(handle, name, &v, result,
+				sizeof(*result));
+	} else {
+		ret =  sony_nc_buffer_call(handle, name, NULL, result,
+				sizeof(*result));
+	}
+	return ret;
+}
+
 struct sony_nc_handles {
 	u16 cap[0x10];
 	struct device_attribute devattr;