[Entrypoints] Support Online Serving for Diffusion-only Models (#259)

Signed-off-by: Chenguang ZHENG <645327136@qq.com>
Signed-off-by: yinpe <11810305@mail.sustech.edu.cn>
Co-authored-by: yinpe <11810305@mail.sustech.edu.cn>

vllm_omni/diffusion/data.py

@@ -388,6 +388,26 @@ class OmniDiffusionConfig:
                 f"num_gpus ({self.num_gpus}) < parallel_config.world_size ({self.parallel_config.world_size})"
             )
 
+        # Convert string dtype to torch.dtype if needed
+        if isinstance(self.dtype, str):
+            dtype_map = {
+                "auto": torch.bfloat16,
+                "bfloat16": torch.bfloat16,
+                "bf16": torch.bfloat16,
+                "float16": torch.float16,
+                "fp16": torch.float16,
+                "half": torch.float16,
+                "float32": torch.float32,
+                "fp32": torch.float32,
+                "float": torch.float32,
+            }
+            dtype_lower = self.dtype.lower()
+            if dtype_lower in dtype_map:
+                self.dtype = dtype_map[dtype_lower]
+            else:
+                logger.warning(f"Unknown dtype string '{self.dtype}', defaulting to bfloat16")
+                self.dtype = torch.bfloat16
+
         # Convert cache_config dict to DiffusionCacheConfig if needed
         if isinstance(self.cache_config, dict):
             self.cache_config = DiffusionCacheConfig.from_dict(self.cache_config)