Restore AttnProcessor2_0 in unload_ip_adapter (#7727)

* Restore AttnProcessor2_0 in unload_ip_adapter

* Fix style

* Update test

---------
Co-authored-by: YiYi Xu <yixu310@gmail.com>

src/diffusers/loaders/ip_adapter.py

@@ -16,6 +16,7 @@ from pathlib import Path
 from typing import Dict, List, Optional, Union
 
 import torch
+import torch.nn.functional as F
 from huggingface_hub.utils import validate_hf_hub_args
 from safetensors import safe_open
 
@@ -38,6 +39,8 @@ if is_transformers_available():
     )
 
     from ..models.attention_processor import (
+        AttnProcessor,
+        AttnProcessor2_0,
         IPAdapterAttnProcessor,
         IPAdapterAttnProcessor2_0,
     )
@@ -323,4 +326,14 @@ class IPAdapterMixin:
         self.config.encoder_hid_dim_type = None
 
         # restore original Unet attention processors layers
-        self.unet.set_default_attn_processor()
+        attn_procs = {}
+        for name, value in self.unet.attn_processors.items():
+            attn_processor_class = (
+                AttnProcessor2_0() if hasattr(F, "scaled_dot_product_attention") else AttnProcessor()
+            )
+            attn_procs[name] = (
+                attn_processor_class
+                if isinstance(value, (IPAdapterAttnProcessor, IPAdapterAttnProcessor2_0))
+                else value.__class__()
+            )
+        self.unet.set_attn_processor(attn_procs)

tests/pipelines/ip_adapters/test_ip_adapter_stable_diffusion.py

@@ -32,7 +32,6 @@ from diffusers import (
     StableDiffusionXLPipeline,
 )
 from diffusers.image_processor import IPAdapterMaskProcessor
-from diffusers.models.attention_processor import AttnProcessor, AttnProcessor2_0
 from diffusers.utils import load_image
 from diffusers.utils.testing_utils import (
     enable_full_determinism,
@@ -307,6 +306,7 @@ class IPAdapterSDIntegrationTests(IPAdapterNightlyTestsMixin):
         pipeline = StableDiffusionPipeline.from_pretrained(
             "runwayml/stable-diffusion-v1-5", image_encoder=image_encoder, safety_checker=None, torch_dtype=self.dtype
         )
+        before_processors = [attn_proc.__class__ for attn_proc in pipeline.unet.attn_processors.values()]
         pipeline.to(torch_device)
         pipeline.load_ip_adapter("h94/IP-Adapter", subfolder="models", weight_name="ip-adapter_sd15.bin")
         pipeline.set_ip_adapter_scale(0.7)
@@ -315,11 +315,9 @@ class IPAdapterSDIntegrationTests(IPAdapterNightlyTestsMixin):
 
         assert getattr(pipeline, "image_encoder") is None
         assert getattr(pipeline, "feature_extractor") is not None
-        processors = [
-            isinstance(attn_proc, (AttnProcessor, AttnProcessor2_0))
-            for name, attn_proc in pipeline.unet.attn_processors.items()
-        ]
-        assert processors == [True] * len(processors)
+        after_processors = [attn_proc.__class__ for attn_proc in pipeline.unet.attn_processors.values()]
+
+        assert before_processors == after_processors
 
     @is_flaky
     def test_multi(self):