fix generation config

Author: echarlaix

optimum/intel/openvino/modeling_base.py

@@ -127,8 +127,10 @@ def __init__(
         self.output_dtypes = output_dtypes
         self.model = model
         self.request = None if not self._compile_only else self.model
+
+        generation_config = kwargs.get("generation_config", None)
         if self.can_generate():
-            self.generation_config = kwargs.get("generation_config", GenerationConfig.from_model_config(config))
+            self.generation_config = generation_config or GenerationConfig.from_model_config(config)
 
             if is_transformers_version(">=", "4.44.99"):
                 misplaced_generation_parameters = self.config._get_non_default_generation_parameters()

optimum/intel/openvino/modeling_base_seq2seq.py

@@ -80,7 +80,8 @@ def __init__(
         self.decoder_model = decoder
         self.decoder_with_past_model = decoder_with_past
 
-        self.generation_config = kwargs.get("generation_config", GenerationConfig.from_model_config(config))
+        generation_config = kwargs.get("generation_config", None)
+        self.generation_config = generation_config or GenerationConfig.from_model_config(config)
 
         if is_transformers_version(">=", "4.44.99"):
             misplaced_generation_parameters = self.config._get_non_default_generation_parameters()