greybus: loopback: Fix incoherency in calculations in the case of error

Currently, in case the case of error, statistics are updated for
asynchronous but not for an asynchronous operation.
Do not update the statistics in the case of error.
Signed-off-by: NAlexandre Bailon <abailon@baylibre.com>
Reviewed-by: NJohan Hovold <johan@hovoldconsulting.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/loopback.c

@@ -398,10 +398,8 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type,
 	do_gettimeofday(&ts);
 	operation = gb_operation_create(gb->connection, type, request_size,
 					response_size, GFP_KERNEL);
-	if (!operation) {
-		ret = -ENOMEM;
-		goto error;
-	}
+	if (!operation)
+		return -ENOMEM;
 
 	if (request_size)
 		memcpy(operation->request->payload, request, request_size);
@@ -410,6 +408,7 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type,
 	if (ret) {
 		dev_err(&gb->connection->bundle->dev,
 			"synchronous operation failed: %d\n", ret);
+		goto out_put_operation;
 	} else {
 		if (response_size == operation->response->payload_size) {
 			memcpy(response, operation->response->payload,
@@ -419,18 +418,20 @@ static int gb_loopback_operation_sync(struct gb_loopback *gb, int type,
 				"response size %zu expected %d\n",
 				operation->response->payload_size,
 				response_size);
+			ret = -EINVAL;
+			goto out_put_operation;
 		}
 	}
 
-	gb_operation_put(operation);
-
-error:
 	do_gettimeofday(&te);
 
 	/* Calculate the total time the message took */
 	gb_loopback_push_latency_ts(gb, &ts, &te);
 	gb->elapsed_nsecs = gb_loopback_calc_latency(&ts, &te);
 
+out_put_operation:
+	gb_operation_put(operation);
+
 	return ret;
 }
 
@@ -988,8 +989,9 @@ static int gb_loopback_fn(void *data)
 
 			if (error)
 				gb->error++;
+			else
+				gb_loopback_calculate_stats(gb);
 			gb->iteration_count++;
-			gb_loopback_calculate_stats(gb);
 		}
 		send_count++;
 		if (us_wait)