From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] pinctrl: coh901: constify gpio_chip structure Date: Tue, 11 Jul 2017 16:35:19 -0500 Message-ID: <20170711213519.GA3391@embeddedgus> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from gateway22.websitewelcome.com ([192.185.46.234]:36542 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932159AbdGKVfW (ORCPT ); Tue, 11 Jul 2017 17:35:22 -0400 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 0F1EB30205 for ; Tue, 11 Jul 2017 16:35:20 -0500 (CDT) Content-Disposition: inline Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" 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