From 67a76aafec00db46fbd65d7d17a1cde1adde70c5 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 10 Dec 2015 15:55:29 +0100 Subject: [PATCH] gpio: generic: clamp values from bgpio_get_set() The bgpio_get_set() call should return a value clamped to [0,1], the current code will return a negative value if reading bit 31, which turns the value negative as this is a signed value and thus gets interpreted as an error by the gpiolib core. Found on the gpio-mxc but applies to any MMIO driver. Cc: stable@vger.kernel.org # 4.3+ Cc: kernel@pengutronix.de Cc: Vladimir Zapolskiy Fixes: e20538b82f1f ("gpio: Propagate errors from chip->get()") Reported-by: Clemens Gruber Signed-off-by: Linus Walleij --- drivers/gpio/gpio-generic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c index bd5193c..88ae70d 100644 --- a/drivers/gpio/gpio-generic.c +++ b/drivers/gpio/gpio-generic.c @@ -141,9 +141,9 @@ static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio) unsigned long pinmask = bgc->pin2mask(bgc, gpio); if (bgc->dir & pinmask) - return bgc->read_reg(bgc->reg_set) & pinmask; + return !!(bgc->read_reg(bgc->reg_set) & pinmask); else - return bgc->read_reg(bgc->reg_dat) & pinmask; + return !!(bgc->read_reg(bgc->reg_dat) & pinmask); } static int bgpio_get(struct gpio_chip *gc, unsigned int gpio) -- 2.7.4