[Bugfix][Qwen][DCA] fixes bug in dual-chunk-flash-attn backend for qwen 1m models. (vllm-project#21364)

Signed-off-by: Tao He <linzhu.ht@alibaba-inc.com>

Author: sighingnow

vllm/attention/backends/dual_chunk_flash_attn.py

@@ -1055,7 +1055,6 @@ def _dual_chunk_flash_attn_prefill_func(
                     v_states_intra,
                     softmax_scale=softmax_scale,
                     causal=True,
-                    block_table=block_table,
                     stage="intra",
                     vertical_indices=vertical_buffer,
                     slash_indices=slash_buffer,
@@ -1070,7 +1069,6 @@ def _dual_chunk_flash_attn_prefill_func(
                     v_states_intra,
                     softmax_scale=softmax_scale,
                     causal=True,
-                    block_table=block_table,
                     stage="intra",
                     vertical_indices=intra_vertical_indices,
                     slash_indices=intra_slash_indices,
@@ -1085,7 +1083,6 @@ def _dual_chunk_flash_attn_prefill_func(
                         v_states_succ,
                         softmax_scale=softmax_scale,
                         causal=False,
-                        block_table=block_table,
                         stage="succ",
                         vertical_indices=succ_vertical_buffer,
                         slash_indices=succ_slash_buffer,
@@ -1100,7 +1097,6 @@ def _dual_chunk_flash_attn_prefill_func(
                         v_states_succ,
                         softmax_scale=softmax_scale,
                         causal=False,
-                        block_table=block_table,
                         stage="succ",
                         vertical_indices=succ_vertical_indices,
                         slash_indices=succ_slash_indices,
@@ -1115,7 +1111,6 @@ def _dual_chunk_flash_attn_prefill_func(
                         v_states_inter,
                         softmax_scale=softmax_scale,
                         causal=False,
-                        block_table=block_table,
                         stage="inter",
                         vertical_indices=inter_vertical_buffer,
                         slash_indices=inter_slash_buffer,
@@ -1130,7 +1125,6 @@ def _dual_chunk_flash_attn_prefill_func(
                         v_states_inter,
                         softmax_scale=softmax_scale,
                         causal=False,
-                        block_table=block_table,
                         stage="inter",
                         vertical_indices=inter_vertical_indices,
                         slash_indices=inter_slash_indices,
@@ -1151,7 +1145,6 @@ def _do_flash_attn(
         value_states: torch.Tensor,
         softmax_scale: float,
         causal: bool = True,
-        block_table: torch.Tensor = None,
         max_seqlen_k: Optional[int] = None,
         stage: str = "intra",
         vertical_indices: Optional[torch.Tensor] = None,
@@ -1230,7 +1223,6 @@ def _do_flash_attn(
                                       device=query_states.device),
             max_seqlen_k=max_seqlen_k,
             causal=causal,
-            block_table=block_table.unsqueeze(0),
             return_softmax_lse=True,
         )
         softmax_lse = softmax_lse.view(q_len, q_heads, 1).transpose(0,