Author: Julia Lawall <julia@diku.dk> request_mem_region should be used when ioremap is used subsequently. release_region is then correspondingly replaced by release_mem_region. The semantic patch that fixes this problem is as follows: (http://coccinelle.lip6.fr/) // @r@ expression start,E; @@ – request_region + request_mem_region (start,…) … when != request_mem_region(start,…) when != start = E ioremap(start,…) @@ expression r.start; @@ …