Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933940AbdGKVfZ (ORCPT ); Tue, 11 Jul 2017 17:35:25 -0400 Received: from gateway34.websitewelcome.com ([192.185.148.164]:22748 "EHLO gateway34.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933396AbdGKVfW (ORCPT ); Tue, 11 Jul 2017 17:35:22 -0400 Date: Tue, 11 Jul 2017 16:35:19 -0500 From: "Gustavo A. R. Silva" To: Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] pinctrl: coh901: constify gpio_chip structure Message-ID: <20170711213519.GA3391@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.152.228.197 X-Exim-ID: 1dV2oR-001mT6-R8 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.152.228.197]:57874 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 13 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1607 Lines: 64 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 12775 3696 64 16535 4097 drivers/pinctrl/pinctrl-coh901.o after: bss dec hex filename 12440 3640 64 16144 3f10 drivers/pinctrl/pinctrl-coh901.o Signed-off-by: Gustavo A. R. Silva --- drivers/pinctrl/pinctrl-coh901.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pinctrl/pinctrl-coh901.c b/drivers/pinctrl/pinctrl-coh901.c index 741b39e..ac155e7 100644 --- a/drivers/pinctrl/pinctrl-coh901.c +++ b/drivers/pinctrl/pinctrl-coh901.c @@ -387,7 +387,7 @@ int u300_gpio_config_set(struct gpio_chip *chip, unsigned offset, return 0; } -static struct gpio_chip u300_gpio_chip = { +static const struct gpio_chip u300_gpio_chip = { .label = "u300-gpio-chip", .owner = THIS_MODULE, .request = gpiochip_generic_request, -- 2.5.0