[Bugfix] Scope Bagel FP8 config to diffusion stage (#6085)

Signed-off-by: natureofnature <wzliu@connect.hku.hk>
Co-authored-by: Alicia <115451386+congw729@users.noreply.github.com>

tests/diffusion/quantization/test_quantization_fp8.py

@@ -189,7 +189,7 @@ def _generate_single_stage_video(
 
 
 def _generate_bagel_image(
-    quantization_config: str | None = None,
+    diffusion_quantization_config: str | None = None,
     num_inference_steps: int = 15,
 ) -> tuple[Any, float]:
     """Generate an image with BAGEL (multi-stage: LLM + Diffusion).
@@ -202,8 +202,8 @@ def _generate_bagel_image(
         "stage_configs_path": config_path,
         "stage_init_timeout": 300,
     }
-    if quantization_config:
-        omni_kwargs["quantization_config"] = quantization_config
+    if diffusion_quantization_config:
+        omni_kwargs["diffusion_quantization_config"] = diffusion_quantization_config
 
     model_name = omni_kwargs.pop("model")
     with OmniRunner(model_name, **omni_kwargs) as runner:
@@ -380,21 +380,21 @@ def test_single_stage_ltx2_fp8_uses_less_memory():
 
 @hardware_test(res={"cuda": "H100"})
 def test_bagel_fp8_generates_image():
-    """BAGEL with FP8 quantization_config generates a valid image.
+    """BAGEL with diffusion-stage FP8 generates a valid image.
 
     FP8 should only apply to the diffusion stage (Stage-1), not the
     LLM stage (Stage-0). We verify this by checking:
       1. Image is generated successfully
       2. LLM stage finish_reason is 'stop' (not 'length' from garbled output)
     """
-    image, _ = _generate_bagel_image(quantization_config="fp8")
+    image, _ = _generate_bagel_image(diffusion_quantization_config="fp8")
     image.save("test_bagel_fp8.png")
 
 
 @hardware_test(res={"cuda": "H100"})
 def test_bagel_bf16_generates_image():
     """BAGEL without quantization generates a valid image (baseline)."""
-    image, _ = _generate_bagel_image(quantization_config=None)
+    image, _ = _generate_bagel_image(diffusion_quantization_config=None)
     image.save("test_bagel_bf16.png")