HellaCacheArbiter passes through if n == 1

rocket/src/main/scala/arbiter.scala

@@ -13,6 +13,9 @@ class HellaCacheArbiter(n: Int)(implicit p: Parameters) extends Module
     val mem = new HellaCacheIO
   }
 
+  if (n == 1) {
+    io.mem <> io.requestor.head
+  } else {
     val s1_id = Reg(UInt())
     val s2_id = Reg(next=s1_id)
 
@@ -58,6 +61,7 @@ class HellaCacheArbiter(n: Int)(implicit p: Parameters) extends Module
 
       io.requestor(i).replay_next := io.mem.replay_next
     }
+  }
 }
 
 class InOrderArbiter[T <: Data, U <: Data](reqTyp: T, respTyp: U, n: Int)