Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752427AbdHBI3h (ORCPT ); Wed, 2 Aug 2017 04:29:37 -0400 Received: from mail-it0-f54.google.com ([209.85.214.54]:37109 "EHLO mail-it0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270AbdHBI3g (ORCPT ); Wed, 2 Aug 2017 04:29:36 -0400 MIME-Version: 1.0 In-Reply-To: <20170711221538.GA8001@embeddedgus> References: <20170711221538.GA8001@embeddedgus> From: Linus Walleij Date: Wed, 2 Aug 2017 10:29:34 +0200 Message-ID: Subject: Re: [PATCH] gpio: altera-a10sr: constify gpio_chip structure To: "Gustavo A. R. Silva" Cc: Thor Thayer , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1259 Lines: 53 On Wed, Jul 12, 2017 at 12:15 AM, Gustavo A. R. Silva wrote: > This structure is only used to copy into another structure, so declare > it as const. > > This issue was detected using Coccinelle and the following semantic patch: > > @r disable optional_qualifier@ > identifier i; > position p; > @@ > static struct gpio_chip i@p = { ... }; > > @ok@ > identifier r.i; > expression e; > position p; > @@ > e = i@p; > > @bad@ > position p != {r.p,ok.p}; > identifier r.i; > struct gpio_chip e; > @@ > e@i@p > > @depends on !bad disable optional_qualifier@ > identifier r.i; > @@ > static > +const > struct gpio_chip i = { ... }; > > In the following log you can see a significant difference in the code size > and data segment, hence in the dec segment. This log is the output > of the size command, before and after the code change: > > before: > text data bss dec hex filename > 1954 600 0 2554 9fa drivers/gpio/gpio-altera-a10sr.o > > after: > text data bss dec hex filename > 1655 512 0 2167 877 drivers/gpio/gpio-altera-a10sr.o > > Signed-off-by: Gustavo A. R. Silva Patch applied with Thor's review tag. Yours, Linus Walleij