Flush transport on timeout during setup

lib/blue_heron/hci/transport.ex

@@ -17,6 +17,12 @@ defmodule BlueHeron.HCI.Transport do
   @type command_complete :: %BlueHeron.HCI.Event.CommandComplete{}
   @type command_status :: %BlueHeron.HCI.Event.CommandStatus{}
 
+  @doc "Checks if setup is complete on the transport"
+  @spec setup_complete?() :: boolean()
+  def setup_complete? do
+    GenServer.call(__MODULE__, :setup_complete?)
+  end
+
   @doc "Send an HCI frame"
   @spec send_hci(map()) ::
           {:ok, command_complete() | command_status()} | {:error, :setup_incomplete | :timeout}
@@ -182,6 +188,7 @@ defmodule BlueHeron.HCI.Transport do
       nil ->
         Logger.warning("Setup command timeout: #{inspect(state.current)}")
         hci_bin = serialize(state.current)
+        :ok = BlueHeron.HCI.Transport.UART.flush(state.transport)
         :ok = BlueHeron.HCI.Transport.UART.send_command(state.transport, hci_bin)
         timer = Process.send_after(self(), :current_timeout, 5000)
         {:noreply, %{new_state | current_timer: timer}}
@@ -309,6 +316,10 @@ defmodule BlueHeron.HCI.Transport do
     {:reply, :ok, state}
   end
 
+  def handle_call(:setup_complete, _from, %{setup_complete: setup_complete} = state) do
+    {:reply, setup_complete, state}
+  end
+
   def handle_call(_call, _from, %{setup_complete: false} = state) do
     {:reply, {:error, :setup_incomplete}, state}
   end

lib/blue_heron/hci/transport/uart.ex

@@ -31,6 +31,12 @@ defmodule BlueHeron.HCI.Transport.UART do
     GenServer.call(pid, {:send, [<<@hci_acl_packet::8>>, acl]})
   end
 
+  @doc "Flush buffers"
+  @spec flush(GenServer.server()) :: :ok
+  def flush(pid) do
+    GenServer.call(pid, :flush)
+  end
+
   ## Server Callbacks
 
   @impl GenServer
@@ -48,6 +54,10 @@ defmodule BlueHeron.HCI.Transport.UART do
     {:reply, UART.write(uart_pid, command), state}
   end
 
+  def handle_call(:flush, _from, %{uart_pid: uart_pid} = state) do
+    {:reply, UART.flush(uart_pid), state}
+  end
+
   @impl GenServer
   def handle_info({:open, device, opts}, state) when is_binary(device) and is_list(opts) do
     case UART.open(state.uart_pid, device, opts) do