diff --git a/vllm/model_executor/layers/mamba/mamba_mixer2.py b/vllm/model_executor/layers/mamba/mamba_mixer2.py
index 4ca8e6b97fce..4e473bda1fe2 100644
--- a/vllm/model_executor/layers/mamba/mamba_mixer2.py
+++ b/vllm/model_executor/layers/mamba/mamba_mixer2.py
@@ -583,8 +583,8 @@ def forward_cuda(
             x = hidden_states_B_C_p.transpose(
                 0, 1)  # this is the form that causal-conv see
             if mamba2_metadata.cu_seqlen is None:
-                mamba2_metadata = update_metadata(
-                    x, attn_metadata.query_start_loc, mamba2_metadata)
+                mamba2_metadata = update_metadata(x, query_start_loc_p,
+                                                  mamba2_metadata)
             hidden_states_B_C_p = causal_conv1d_fn(
                 x,
                 conv_weights,
@@ -593,6 +593,7 @@ def forward_cuda(
                 conv_states=conv_state,
                 has_initial_state=has_initial_states_p,
                 cache_indices=state_indices_tensor_p,
+                metadata=mamba2_metadata,
                 query_start_loc=query_start_loc_p).transpose(
                     0, 1)[:num_prefill_tokens]
 
@@ -603,9 +604,14 @@ def forward_cuda(
             initial_states = None
             if (has_initial_states_p is not None and prep_initial_states):
                 # making a copy of the states
-                initial_states = torch.where(
-                    has_initial_states_p[:, None, None, None],
-                    ssm_state[state_indices_tensor_p], 0)
+                if envs.VLLM_USE_V1:
+                    initial_states = torch.where(
+                        has_initial_states_p[:, None, None, None],
+                        ssm_state[state_indices_tensor_p], 0)
+                else:
+                    initial_states = torch.where(
+                        has_initial_states_p[:num_prefills, None, None, None],
+                        ssm_state[state_indices_tensor_p], 0)
 
             scan_output, varlen_state = mamba_chunk_scan_combined(
                 hidden_states_p.view(1, num_prefill_tokens,
diff --git a/vllm/model_executor/layers/mamba/ops/causal_conv1d.py b/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
index a8bd0067bf45..b8d4bbc37105 100644
--- a/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
+++ b/vllm/model_executor/layers/mamba/ops/causal_conv1d.py
@@ -55,7 +55,6 @@ def _causal_conv1d_fwd_kernel(  # continuous batching
     IS_CONTINUOUS_BATCHING: tl.constexpr,
     USE_PAD_SLOT: tl.constexpr,
     NP2_STATELEN: tl.constexpr,
-    DECODE_SEQLEN: tl.constexpr,
     BLOCK_M: tl.constexpr,
     BLOCK_N: tl.constexpr,
 ):
@@ -416,7 +415,7 @@ def causal_conv1d_fn(
         activation = "silu"
 
     args = None
-    out = torch.zeros_like(x)
+    out = torch.empty_like(x)
     if metadata is not None:
         cu_seqlen = metadata.cu_seqlen
         nums_dict = metadata.nums_dict
@@ -607,7 +606,6 @@ def grid(META):
         IS_CONTINUOUS_BATCHING=cache_indices is not None,
         USE_PAD_SLOT=pad_slot_id is not None,
         NP2_STATELEN=np2_statelen,
-        DECODE_SEQLEN=1,
         #launch_cooperative_grid=True
         BLOCK_M=8,
         BLOCK_N=256,
@@ -665,7 +663,8 @@ def _causal_conv1d_update_kernel(
 
     if IS_CONTINUOUS_BATCHING:
         # mask = idx_seq < batch
-        conv_state_batch_coord = tl.load(conv_state_indices_ptr + idx_seq)
+        conv_state_batch_coord = tl.load(conv_state_indices_ptr + idx_seq).to(
+            tl.int64)
     else:
         conv_state_batch_coord = idx_seq
     if USE_PAD_SLOT:  # noqa