Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756055AbdGKSDo (ORCPT ); Tue, 11 Jul 2017 14:03:44 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.109]:34483 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755802AbdGKSDn (ORCPT ); Tue, 11 Jul 2017 14:03:43 -0400 Date: Tue, 11 Jul 2017 13:03:39 -0500 From: "Gustavo A. R. Silva" To: Linus Walleij , Florian Fainelli , Ray Jui , Scott Branden , Eric Anholt , Stefan Wahren Cc: bcm-kernel-feedback-list@broadcom.com, linux-gpio@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] pinctrl: bcm2835: constify gpio_chip structure Message-ID: <20170711180339.GA17806@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: 189.152.152.176 X-Exim-ID: 1dUzVc-0027Vx-Ha X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.152.152.176]:59716 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 11 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1692 Lines: 64 This structure is only used to copy into other 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 18958 9000 128 28086 6db6 drivers/pinctrl/bcm/pinctrl-bcm2835.o after: text data bss dec hex filename 18764 8912 128 27804 6c9c drivers/pinctrl/bcm/pinctrl-bcm2835.o Signed-off-by: Gustavo A. R. Silva --- drivers/pinctrl/bcm/pinctrl-bcm2835.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c index 2308831..7203f35 100644 --- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c +++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c @@ -353,7 +353,7 @@ static int bcm2835_gpio_direction_output(struct gpio_chip *chip, return pinctrl_gpio_direction_output(chip->base + offset); } -static struct gpio_chip bcm2835_gpio_chip = { +static const struct gpio_chip bcm2835_gpio_chip = { .label = MODULE_NAME, .owner = THIS_MODULE, .request = gpiochip_generic_request, -- 2.5.0