Fix encoder-decoder model disabling mm processor cache (#33236)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

tests/models/multimodal/processing/test_common.py

@@ -241,14 +241,15 @@ def _test_processing_correctness(
         revision=model_info.revision,
         trust_remote_code=model_info.trust_remote_code,
         hf_overrides=model_info.hf_overrides,
-        # Ensure that the cache can fit all of the data
-        mm_processor_cache_gb=2048,
         skip_tokenizer_init=model_info.require_embed_inputs,
         enable_prompt_embeds=model_info.require_embed_inputs,
         enable_mm_embeds=model_info.require_embed_inputs,
         enforce_eager=model_info.enforce_eager,
         dtype=model_info.dtype,
     )
+    # Ensure that the cache can fit all of the data
+    # (set after because ModelConfig would set it to 0 for encoder-decoder models)
+    model_config.multimodal_config.mm_processor_cache_gb = 2048
 
     model_cls = MULTIMODAL_REGISTRY._get_model_cls(model_config)
     factories = model_cls._processor_factory

vllm/config/model.py

@@ -572,7 +572,7 @@ class ModelConfig:
         self.max_model_len = self.get_and_verify_max_len(self.max_model_len)
 
         if self.is_encoder_decoder:
-            self.mm_processor_cache_gb = 0
+            mm_processor_cache_gb = 0
             logger.info("Encoder-decoder model detected, disabling mm processor cache.")
 
         # Init multimodal config if needed