diff --git a/lib/membrane/core/callback_handler.ex b/lib/membrane/core/callback_handler.ex
index 41c870077..c42a7400c 100644
--- a/lib/membrane/core/callback_handler.ex
+++ b/lib/membrane/core/callback_handler.ex
@@ -30,7 +30,7 @@ defmodule Membrane.Core.CallbackHandler do
   @callback transform_actions(actions :: list, callback :: atom, handler_params, state) ::
               {actions :: list, state}
 
-  @callback handle_end_of_actions(callback :: atom, state) :: state
+  @callback handle_end_of_actions(state) :: state
 
   defmacro __using__(_args) do
     quote location: :keep do
@@ -43,7 +43,7 @@ defmodule Membrane.Core.CallbackHandler do
       end
 
       @impl unquote(__MODULE__)
-      def handle_end_of_actions(_callback, state) do
+      def handle_end_of_actions(state) do
         state
       end
 
@@ -202,6 +202,6 @@ defmodule Membrane.Core.CallbackHandler do
         end
       end)
 
-    handler_module.handle_end_of_actions(callback, state)
+    handler_module.handle_end_of_actions(state)
   end
 end
diff --git a/lib/membrane/core/element.ex b/lib/membrane/core/element.ex
index 3299c305c..bf9ab243e 100644
--- a/lib/membrane/core/element.ex
+++ b/lib/membrane/core/element.ex
@@ -215,7 +215,7 @@ defmodule Membrane.Core.Element do
 
   defp do_handle_info(Message.new(:buffer, buffers, _opts) = msg, state) do
     pad_ref = Message.for_pad(msg)
-    state = BufferController.handle_ingoing_buffers(pad_ref, buffers, state)
+    state = BufferController.handle_incoming_buffers(pad_ref, buffers, state)
     {:noreply, state}
   end
 
diff --git a/lib/membrane/core/element/action_handler.ex b/lib/membrane/core/element/action_handler.ex
index 12914f4a9..d6027870d 100644
--- a/lib/membrane/core/element/action_handler.ex
+++ b/lib/membrane/core/element/action_handler.ex
@@ -45,14 +45,8 @@ defmodule Membrane.Core.Element.ActionHandler do
 
   defguardp is_demand_size(size) when is_integer(size) or is_function(size)
 
-  # Match in the function below is caused by a fact, that handle_spec_started is the only callback, that
-  # might be executed in between handling actions returned from other callbacks.
-  # This callback has been deprecated and should be removed in v2.0.0, along with the if statement below.
-
   @impl CallbackHandler
-  def handle_end_of_actions(:handle_spec_started, state), do: state
-
-  def handle_end_of_actions(_callback, state) do
+  def handle_end_of_actions(state) do
     # Fixed order of handling demand of manual and auto pads would lead to
     # favoring manual pads over auto pads (or vice versa), especially after
     # introducting auto flow queues.
diff --git a/lib/membrane/core/element/buffer_controller.ex b/lib/membrane/core/element/buffer_controller.ex
index 2fcd3d9cb..d275502d3 100644
--- a/lib/membrane/core/element/buffer_controller.ex
+++ b/lib/membrane/core/element/buffer_controller.ex
@@ -31,8 +31,8 @@ defmodule Membrane.Core.Element.BufferController do
   callback. Also calls `Membrane.Core.Element.ManualFlowController.supply_demand/2`
   to check if there are any unsupplied demands.
   """
-  @spec handle_ingoing_buffers(Pad.ref(), [Buffer.t()] | Buffer.t(), State.t()) :: State.t()
-  def handle_ingoing_buffers(pad_ref, buffers, state) do
+  @spec handle_incoming_buffers(Pad.ref(), [Buffer.t()] | Buffer.t(), State.t()) :: State.t()
+  def handle_incoming_buffers(pad_ref, buffers, state) do
     withl pad: {:ok, data} <- PadModel.get_data(state, pad_ref),
           playback: %State{playback: :playing} <- state do
       %{
@@ -50,25 +50,25 @@ defmodule Membrane.Core.Element.BufferController do
           EventController.handle_start_of_stream(pad_ref, state)
         end
 
-      do_handle_ingoing_buffers(pad_ref, data, buffers, state)
+      do_handle_incoming_buffers(pad_ref, data, buffers, state)
     else
       pad: {:error, :unknown_pad} ->
         # We've got a buffer from already unlinked pad
         state
 
       playback: _playback ->
-        PlaybackQueue.store(&handle_ingoing_buffers(pad_ref, buffers, &1), state)
+        PlaybackQueue.store(&handle_incoming_buffers(pad_ref, buffers, &1), state)
     end
   end
 
-  @spec do_handle_ingoing_buffers(
+  @spec do_handle_incoming_buffers(
           Pad.ref(),
           PadModel.pad_data(),
           [Buffer.t()] | Buffer.t(),
           State.t()
         ) ::
           State.t()
-  defp do_handle_ingoing_buffers(pad_ref, %{flow_control: :auto} = data, buffers, state) do
+  defp do_handle_incoming_buffers(pad_ref, %{flow_control: :auto} = data, buffers, state) do
     %{demand: demand, demand_unit: demand_unit, stalker_metrics: stalker_metrics} = data
     buf_size = Buffer.Metric.from_unit(demand_unit).buffers_size(buffers)
 
@@ -83,7 +83,7 @@ defmodule Membrane.Core.Element.BufferController do
     end
   end
 
-  defp do_handle_ingoing_buffers(pad_ref, %{flow_control: :manual} = data, buffers, state) do
+  defp do_handle_incoming_buffers(pad_ref, %{flow_control: :manual} = data, buffers, state) do
     %{input_queue: old_input_queue} = data
 
     input_queue = InputQueue.store(old_input_queue, buffers)
@@ -96,7 +96,7 @@ defmodule Membrane.Core.Element.BufferController do
     end
   end
 
-  defp do_handle_ingoing_buffers(pad_ref, %{flow_control: :push}, buffers, state) do
+  defp do_handle_incoming_buffers(pad_ref, %{flow_control: :push}, buffers, state) do
     exec_buffer_callback(pad_ref, buffers, state)
   end
 
diff --git a/lib/membrane/core/element/demand_controller.ex b/lib/membrane/core/element/demand_controller.ex
index 1f7d99de4..f4d6f7c7d 100644
--- a/lib/membrane/core/element/demand_controller.ex
+++ b/lib/membrane/core/element/demand_controller.ex
@@ -30,7 +30,7 @@ defmodule Membrane.Core.Element.DemandController do
     with {:ok, pad_data} when not pad_data.end_of_stream? <- PadModel.get_data(state, pad_ref),
          %State{playback: :playing} <- state do
       if pad_data.direction == :input do
-        raise("cannot snapshot atomic counter in input pad")
+        raise("cannot snapshot atomic counter in input pad #{inspect(pad_ref)}")
       end
 
       do_snapshot_atomic_demand(pad_data, state)
diff --git a/lib/membrane/core/pipeline/action_handler.ex b/lib/membrane/core/pipeline/action_handler.ex
index 7b4ebe153..382a4f5a8 100644
--- a/lib/membrane/core/pipeline/action_handler.ex
+++ b/lib/membrane/core/pipeline/action_handler.ex
@@ -107,7 +107,7 @@ defmodule Membrane.Core.Pipeline.ActionHandler do
   end
 
   @impl CallbackHandler
-  def handle_end_of_actions(_callback, state) do
+  def handle_end_of_actions(state) do
     with %{awaiting_setup_completition?: true} <- state do
       %{state | awaiting_setup_completition?: false}
       |> Membrane.Core.LifecycleController.complete_setup()