Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756779AbdGLHER (ORCPT ); Wed, 12 Jul 2017 03:04:17 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:10298 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756720AbdGLHEP (ORCPT ); Wed, 12 Jul 2017 03:04:15 -0400 From: Patrice CHOTARD To: "Gustavo A. R. Silva" , Linus Walleij CC: "linux-arm-kernel@lists.infradead.org" , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] pinctrl: st: constify gpio_chip structure Thread-Topic: [PATCH] pinctrl: st: constify gpio_chip structure Thread-Index: AQHS+nGpP7ES9vnJPEKY9T6F/ysjA6JPo4OA Date: Wed, 12 Jul 2017 07:03:29 +0000 Message-ID: References: <20170711181519.GA20001@embeddedgus> In-Reply-To: <20170711181519.GA20001@embeddedgus> Accept-Language: fr-FR, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.51] Content-Type: text/plain; charset="utf-8" Content-ID: <25A816E9D3135649BB74A283ADF4C2BA@st.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-12_01:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v6C74TK4009820 Content-Length: 1858 Lines: 70 Hi Gustavo On 07/11/2017 08:15 PM, Gustavo A. R. Silva wrote: > 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 > 21671 3632 128 25431 6357 drivers/pinctrl/pinctrl-st.o > > after: > text data bss dec hex filename > 21366 3576 128 25070 61ee drivers/pinctrl/pinctrl-st.o > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/pinctrl/pinctrl-st.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c > index 3ae8066..5d4789d 100644 > --- a/drivers/pinctrl/pinctrl-st.c > +++ b/drivers/pinctrl/pinctrl-st.c > @@ -1442,7 +1442,7 @@ static void st_gpio_irqmux_handler(struct irq_desc *desc) > chained_irq_exit(chip, desc); > } > > -static struct gpio_chip st_gpio_template = { > +static const struct gpio_chip st_gpio_template = { > .request = gpiochip_generic_request, > .free = gpiochip_generic_free, > .get = st_gpio_get, > Acked-by: Patrice Chotard Thanks