From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from vs81.iboxed.net ([185.82.85.146]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dTDoH-0000W6-Fi for barebox@lists.infradead.org; Thu, 06 Jul 2017 20:55:40 +0000 Date: Thu, 6 Jul 2017 22:53:38 +0200 (CEST) From: Alexander Kurz In-Reply-To: <1499345180.22075.58.camel@pengutronix.de> Message-ID: References: <20170705182747.GB13920@ravnborg.org> <20170705183315.GB17038@ravnborg.org> <1499345180.22075.58.camel@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 2/3] gpio: fix null pointer exception when there is no oftree To: Lucas Stach Cc: barebox@lists.infradead.org, Sam Ravnborg , =?ISO-8859-15?Q?Uwe_Kleine-K=F6nig?= On Thu, 6 Jul 2017, Lucas Stach wrote: > Am Mittwoch, den 05.07.2017, 20:33 +0200 schrieb Sam Ravnborg: > > From d10f426e1b8cec7de257dabf59e7fe53a591b3c1 Mon Sep 17 00:00:00 2001 > > From: Sam Ravnborg > > Date: Mon, 3 Jul 2017 22:07:41 +0200 > > Subject: [PATCH 2/3] gpio: fix null pointer exception when there is no oftree > > > > In a system with oftree support enabled but with no oftree the > > of_gpiochip_scan_hogs() would fail due to device_node equals NULL. > > > > Check device_node and return with 0 in this situation, as this > > mirrors what would have happened before we added support for gpio-hogs. > > > > Use IS_ENABLED(CONFIG_OFDEVICE) to teach compiler to leave > > out the of_* specific functions if not needed. > > > > Fixes: 37e6bee7 ("gpiolib: Add support for GPIO "hog" nodes") > > Signed-off-by: Alexander Kurz > > Signed-off-by: Sam Ravnborg > > --- > > drivers/gpio/gpiolib.c | 8 +++++++- > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > > index a3e17ada0..2bd8ef2a8 100644 > > --- a/drivers/gpio/gpiolib.c > > +++ b/drivers/gpio/gpiolib.c > > @@ -379,6 +379,9 @@ static int of_gpiochip_scan_hogs(struct gpio_chip *chip) > > struct device_node *np; > > int ret, i; > > > > + if (!chip->dev->device_node) > > + return 0; > > + > > for_each_available_child_of_node(chip->dev->device_node, np) { > > if (!of_property_read_bool(np, "gpio-hog")) > > continue; > > @@ -416,7 +419,10 @@ int gpiochip_add(struct gpio_chip *chip) > > for (i = chip->base; i < chip->base + chip->ngpio; i++) > > gpio_desc[i].chip = chip; > > > > - return of_gpiochip_scan_hogs(chip); > > + if (IS_ENABLED(CONFIG_OFDEVICE)) > > + return of_gpiochip_scan_hogs(chip); > > + else > > + return 0; > > } > > > > void gpiochip_remove(struct gpio_chip *chip) > > I think this can be simplified to: > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index a3e17ada0d39..1a373ef149a5 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -379,6 +379,9 @@ static int of_gpiochip_scan_hogs(struct gpio_chip > *chip) > struct device_node *np; > int ret, i; > > + if (!IS_ENABLED(CONFIG_OFDEVICE) || !chip->dev->device_node) > + return 0; > + > for_each_available_child_of_node(chip->dev->device_node, np) { > if (!of_property_read_bool(np, "gpio-hog")) > continue; > > The optimizer should be able to work this out. Can you check that this > works for you? No need to resend, if it works I'll just commit this. This works perfecty fine with gcc-5.2 and gcc-4.6 (although gcc-4.6 compatibilty broke with commit 4ef026c3048) Thanks, Alexander > > Regards, > Lucas > _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox