serial-dmm: No error message upon 0 new bytes.

diff --git a/hardware/serial-dmm/protocol.c b/hardware/serial-dmm/protocol.c
index 6ca5e73ea593346d9c86caf0a489a263776b7c50..fab6c4ae8d25223303400f5c0638ddd84ff54eb5 100644 (file)
--- a/hardware/serial-dmm/protocol.c
+++ b/hardware/serial-dmm/protocol.c
@@ -80,7 +80,9 @@ static void handle_new_data(struct sr_dev_inst *sdi, int dmm, void *info)
        /* Try to get as much data as the buffer can hold. */
        len = DMM_BUFSIZE - devc->buflen;
        len = serial_read(serial, devc->buf + devc->buflen, len);
-       if (len < 1) {
+       if (len == 0)
+               return; /* No new bytes, nothing to do. */
+       if (len < 0) {
                sr_err("Serial port read error: %d.", len);
                return;
        }