[PATCH] lockdep: annotate serio

The PS/2 code has a natural device order and there is a one level recursion in
this device order in terms of the cmd_mutex; annotate this explicit recursion
as ok.

Has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/input/serio/libps2.c

@@ -177,7 +177,7 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
 		return -1;
 	}
 
-	mutex_lock(&ps2dev->cmd_mutex);
+	mutex_lock_nested(&ps2dev->cmd_mutex, SINGLE_DEPTH_NESTING);
 
 	serio_pause_rx(ps2dev->serio);
 	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;