Author: Julia Lawall <julia@diku.dk> IS_ERR returns only 1 or 0. The callsite of setup_regulators expects a negative integer in an error case. Thus, PTR_ERR has to be used to extract it. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression E,E1; @@ *E = IS_ERR(…) … when != E = …