Return-path: Received: from wx-out-0506.google.com ([66.249.82.230]:65361 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758808AbXH3UUZ (ORCPT ); Thu, 30 Aug 2007 16:20:25 -0400 Received: by wx-out-0506.google.com with SMTP id h31so589942wxd for ; Thu, 30 Aug 2007 13:20:24 -0700 (PDT) Message-ID: <9a8748490708301320o49d8e794vc5c37ffc938006f1@mail.gmail.com> Date: Thu, 30 Aug 2007 22:20:23 +0200 From: "Jesper Juhl" To: "Daniel Drake" Subject: Re: [PATCH 13/30] net: Don't do pointless kmalloc return value casts in zd1211 driver Cc: "Linux Kernel Mailing List" , netdev@vger.kernel.org, "David S. Miller" , "Ulrich Kunitz" , linux-wireless@vger.kernel.org In-Reply-To: <46D70467.1040109@gentoo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <1554af80879a7ef2f78a4d654f23c248203500d9.1187912217.git.jesper.juhl@gmail.com> <46D70467.1040109@gentoo.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: On 30/08/2007, Daniel Drake wrote: > Jesper Juhl wrote: > > Since kmalloc() returns a void pointer there is no reason to cast > > its return value. > > This patch also removes a pointless initialization of a variable. > > NAK: adds a sparse warning > zd_chip.c:116:15: warning: implicit cast to nocast type > Ok, I must admit I didn't check with sparse since it seemed pointless - we usually never cast void pointers to other pointer types, specifically because the C language nicely guarantees that the right thing will happen without the cast. Sometimes we have to cast them to integer types, su sure we need the cast there. But what on earth makes a "zd_addr_t *" so special that we have to explicitly cast a "void *" to that type? I see it's defined as typedef u32 __nocast zd_addr_t; in drivers/net/wireless/zd1211rw/zd_types.h , but why the __nocast ? What would be wrong in applying my patch that removes the cast of the kmalloc() return value and then also remove the "__nocast" here? -- Jesper Juhl Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html