Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757405AbcCaP7A (ORCPT ); Thu, 31 Mar 2016 11:59:00 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:38710 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753515AbcCaP67 (ORCPT ); Thu, 31 Mar 2016 11:58:59 -0400 Date: Thu, 31 Mar 2016 08:59:00 -0700 From: Guenter Roeck To: Linus Walleij Cc: Alexandre Courbot , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] gpio: Do not accept gpio chip additions before gpiolib initialization Message-ID: <20160331155900.GA5605@roeck-us.net> References: <1459275638-11717-1-git-send-email-linux@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459275638-11717-1-git-send-email-linux@roeck-us.net> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2127 Lines: 64 On Tue, Mar 29, 2016 at 11:20:38AM -0700, Guenter Roeck wrote: > Since commit ff2b13592299 ("gpio: make the gpiochip a real device"), > attempts to add a gpio chip prior to gpiolib initialization cause the > system to crash. Dump a warning to the console and return an error > if the situation is encountered. > > Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") > Signed-off-by: Guenter Roeck Please drop this one; I think the other series I sent out earlier today is much better. Guenter > --- > drivers/gpio/gpiolib.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 72065532c1c7..ac66219f0611 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -68,6 +68,7 @@ LIST_HEAD(gpio_devices); > static void gpiochip_free_hogs(struct gpio_chip *chip); > static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); > > +static bool gpiolib_initialized; > > static inline void desc_set_label(struct gpio_desc *d, const char *label) > { > @@ -457,6 +458,9 @@ static void gpiodevice_release(struct device *dev) > * the gpio framework's arch_initcall(). Otherwise sysfs initialization > * for GPIOs will fail rudely. > * > + * gpiochip_add_data() must only be called after gpiolib initialization, > + * ie after core_initcall(). > + * > * If chip->base is negative, this requests dynamic assignment of > * a range of valid GPIOs. > */ > @@ -468,6 +472,11 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) > int base = chip->base; > struct gpio_device *gdev; > > + if (!gpiolib_initialized) { > + WARN(1, "gpiolib not initialized\n"); > + return -EPROBE_DEFER; > + } > + > /* > * First: allocate and populate the internal stat container, and > * set up the struct device. > @@ -2829,6 +2838,8 @@ static int __init gpiolib_dev_init(void) > if (ret < 0) { > pr_err("gpiolib: failed to allocate char dev region\n"); > bus_unregister(&gpio_bus_type); > + } else { > + gpiolib_initialized = true; > } > return ret; > } > -- > 2.5.0 >