From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: [PATCH] gpio: Do not accept gpio chip additions before gpiolib initialization Date: Tue, 29 Mar 2016 11:20:38 -0700 Message-ID: <1459275638-11717-1-git-send-email-linux@roeck-us.net> Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:43173 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751595AbcC2SUk (ORCPT ); Tue, 29 Mar 2016 14:20:40 -0400 Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Linus Walleij Cc: Alexandre Courbot , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck 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 --- 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