From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrice CHOTARD Subject: Re: [PATCH] pinctrl: st: constify gpio_chip structure Date: Wed, 12 Jul 2017 07:03:29 +0000 Message-ID: References: <20170711181519.GA20001@embeddedgus> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170711181519.GA20001@embeddedgus> Content-Language: en-US Content-ID: <25A816E9D3135649BB74A283ADF4C2BA@st.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "Gustavo A. R. Silva" , Linus Walleij Cc: "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: linux-gpio@vger.kernel.org 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