diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 4aa7350db3..0ba902e7c0 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,14 @@
+2016-01-26  Yao Qi  <yao.qi@linaro.org>
+
+	* remote-utils.c (remote_close) [!USE_WIN32API]: Ignore SIGIO.
+	(unblock_async_io): Rename to ...
+	(block_unblock_async_io): ... it.  New function.
+	(enable_async_io): Don't install SIGIO handler.  Unblock it
+	instead.
+	(disable_async_io): Don't ignore SIGIO.  Block it instead.
+	(initialize_async_io): Install SIGIO handler.  Don't call
+	unblock_async_io.
+
 2016-01-26  Yao Qi  <yao.qi@linaro.org>
 
 	* remote-utils.c (getpkt): If the buffer isn't empty, and the
diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c
index ccc99f16a2..e751473562 100644
--- a/gdb/gdbserver/remote-utils.c
+++ b/gdb/gdbserver/remote-utils.c
@@ -402,6 +402,11 @@ remote_close (void)
 {
   delete_file_handler (remote_desc);
 
+#ifndef USE_WIN32API
+  /* Remove SIGIO handler.  */
+  signal (SIGIO, SIG_IGN);
+#endif
+
 #ifdef USE_WIN32API
   closesocket (remote_desc);
 #else
@@ -775,19 +780,19 @@ check_remote_input_interrupt_request (void)
   input_interrupt (0);
 }
 
-/* Asynchronous I/O support.  SIGIO must be enabled when waiting, in order to
-   accept Control-C from the client, and must be disabled when talking to
-   the client.  */
+/* Asynchronous I/O support.  SIGIO must be unblocked when waiting,
+   in order to accept Control-C from the client, and must be blocked
+   when talking to the client.  */
 
 static void
-unblock_async_io (void)
+block_unblock_async_io (int block)
 {
 #ifndef USE_WIN32API
   sigset_t sigio_set;
 
   sigemptyset (&sigio_set);
   sigaddset (&sigio_set, SIGIO);
-  sigprocmask (SIG_UNBLOCK, &sigio_set, NULL);
+  sigprocmask (block ? SIG_BLOCK : SIG_UNBLOCK, &sigio_set, NULL);
 #endif
 }
 
@@ -823,9 +828,8 @@ enable_async_io (void)
   if (async_io_enabled)
     return;
 
-#ifndef USE_WIN32API
-  signal (SIGIO, input_interrupt);
-#endif
+  block_unblock_async_io (0);
+
   async_io_enabled = 1;
 #ifdef __QNX__
   nto_comctrl (1);
@@ -839,9 +843,8 @@ disable_async_io (void)
   if (!async_io_enabled)
     return;
 
-#ifndef USE_WIN32API
-  signal (SIGIO, SIG_IGN);
-#endif
+  block_unblock_async_io (1);
+
   async_io_enabled = 0;
 #ifdef __QNX__
   nto_comctrl (0);
@@ -852,12 +855,14 @@ disable_async_io (void)
 void
 initialize_async_io (void)
 {
-  /* Make sure that async I/O starts disabled.  */
+  /* Make sure that async I/O starts blocked.  */
   async_io_enabled = 1;
   disable_async_io ();
 
-  /* Make sure the signal is unblocked.  */
-  unblock_async_io ();
+  /* Install the signal handler.  */
+#ifndef USE_WIN32API
+  signal (SIGIO, input_interrupt);
+#endif
 }
 
 /* Internal buffer used by readchar.