Author: Julia Lawall <Julia.Lawall@lip6.fr> devm_ioremap_resource returns an ERR_PTR value, not NULL, on failure. Furthermore, the value returned by devm_ioremap_resource should be tested. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression e,e1; statement S; @@ *e = devm_ioremap_resource(…); if (!e1) S // Signed-off-by: Julia Lawall Signed-off-by: …