remove unused attr, revert to original weight init

mamba/mamba.py

@@ -123,10 +123,6 @@ def __init__(self, config: MambaConfig, use_cache: bool = False):
             padding=self.temporal_width - 1,
         )
 
-        self.scan_fn = selective_scan
-
-        self.resid_proj.weight.data.zero_()
-
     def _ssm(
         self,
         x,
@@ -250,7 +246,12 @@ def __init__(self, config: MambaConfig, use_cache=False):
 
         self.apply(self._init_weights)
 
-        self.lm_head.weight.data.zero_()
+        self.lm_head.weight = self.embed_tokens.weight
+
+        for name, p in self.named_parameters():
+            if name in ["resid_proj.weight"]:
+                nn.init.kaiming_uniform_(p, a=math.sqrt(5))
+                p /= math.sqrt(1.0 * config.num_hidden_layers)
 
     def _init_weights(self, module: nn.Module):
         """Initialize the weights"""