--- src/nvidia_subr.c.orig	2015-12-22 17:54:55.000000000 -0800
+++ src/nvidia_subr.c	2015-12-22 17:55:58.000000000 -0800
@@ -1466,7 +1466,7 @@
 
     if (IS_REG_OFFSET(nv, offset, PAGE_SIZE)) {
         if (IS_BLACKLISTED_REG_OFFSET(nv, offset, PAGE_SIZE)) {
-            return EINVAL;
+             return -1;
         }
         *physical = offset;
         return 0;
