Index: arch/mips/src/exception.c
===================================================================
--- arch/mips/src/exception.c	(revision d2bb9f8a111b1aebb99a97f7a643311460462e4b)
+++ arch/mips/src/exception.c	(revision 3817ed1b528d35beeab51abb588dc261aee19fa8)
@@ -40,5 +40,12 @@
 	__u32 epc_shift = 0;
 	pri_t pri;
-	
+
+	/*
+	 * NOTE ON OPERATION ORDERING
+	 *
+	 * On entry, cpu_priority_high() must be called before exception bit is cleared.
+	 * On exit, exception bit must be set before cpu_priority_restore() is called.
+	 */
+
 	pri = cpu_priority_high();
 	epc = cp0_epc_read();