diff --git a/diffusers_helper/models/hunyuan_video_packed.py b/diffusers_helper/models/hunyuan_video_packed.py
index f879799..1cb42ab 100644
--- a/diffusers_helper/models/hunyuan_video_packed.py
+++ b/diffusers_helper/models/hunyuan_video_packed.py
@@ -122,17 +122,21 @@ def attn_varlen_func(q, k, v, cu_seqlens_q, cu_seqlens_kv, max_seqlen_q, max_seq
         x = torch.nn.functional.scaled_dot_product_attention(q.transpose(1, 2), k.transpose(1, 2), v.transpose(1, 2)).transpose(1, 2)
         return x
 
-    batch_size = q.shape[0]
-    q = q.view(q.shape[0] * q.shape[1], *q.shape[2:])
-    k = k.view(k.shape[0] * k.shape[1], *k.shape[2:])
-    v = v.view(v.shape[0] * v.shape[1], *v.shape[2:])
+    B, L, H, C = q.shape
+
+    q = q.flatten(0, 1)
+    k = k.flatten(0, 1)
+    v = v.flatten(0, 1)
+
     if sageattn_varlen is not None:
         x = sageattn_varlen(q, k, v, cu_seqlens_q, cu_seqlens_kv, max_seqlen_q, max_seqlen_kv)
     elif flash_attn_varlen_func is not None:
         x = flash_attn_varlen_func(q, k, v, cu_seqlens_q, cu_seqlens_kv, max_seqlen_q, max_seqlen_kv)
     else:
         raise NotImplementedError('No Attn Installed!')
-    x = x.view(batch_size, max_seqlen_q, *x.shape[2:])
+
+    x = x.unflatten(0, (B, L))
+
     return x
 
 
@@ -926,23 +930,22 @@ class HunyuanVideoTransformer3DModelPacked(ModelMixin, ConfigMixin, PeftAdapterM
             encoder_hidden_states = torch.cat([extra_encoder_hidden_states, encoder_hidden_states], dim=1)
             encoder_attention_mask = torch.cat([extra_attention_mask, encoder_attention_mask], dim=1)
 
-        with torch.no_grad():
-            if batch_size == 1:
-                # When batch size is 1, we do not need any masks or var-len funcs since cropping is mathematically same to what we want
-                # If they are not same, then their impls are wrong. Ours are always the correct one.
-                text_len = encoder_attention_mask.sum().item()
-                encoder_hidden_states = encoder_hidden_states[:, :text_len]
-                attention_mask = None, None, None, None
-            else:
-                img_seq_len = hidden_states.shape[1]
-                txt_seq_len = encoder_hidden_states.shape[1]
+        if batch_size == 1:
+            # When batch size is 1, we do not need any masks or var-len funcs since cropping is mathematically same to what we want
+            # If they are not same, then their impls are wrong. Ours are always the correct one.
+            text_len = encoder_attention_mask.sum().item()
+            encoder_hidden_states = encoder_hidden_states[:, :text_len]
+            attention_mask = None, None, None, None
+        else:
+            img_seq_len = hidden_states.shape[1]
+            txt_seq_len = encoder_hidden_states.shape[1]
 
-                cu_seqlens_q = get_cu_seqlens(encoder_attention_mask, img_seq_len)
-                cu_seqlens_kv = cu_seqlens_q
-                max_seqlen_q = img_seq_len + txt_seq_len
-                max_seqlen_kv = max_seqlen_q
+            cu_seqlens_q = get_cu_seqlens(encoder_attention_mask, img_seq_len)
+            cu_seqlens_kv = cu_seqlens_q
+            max_seqlen_q = img_seq_len + txt_seq_len
+            max_seqlen_kv = max_seqlen_q
 
-                attention_mask = cu_seqlens_q, cu_seqlens_kv, max_seqlen_q, max_seqlen_kv
+            attention_mask = cu_seqlens_q, cu_seqlens_kv, max_seqlen_q, max_seqlen_kv
 
         if self.enable_teacache:
             modulated_inp = self.transformer_blocks[0].norm1(hidden_states, emb=temb)[0]