From 9c10280d85c14a20751ab6c1185ad725172936d6 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 25 May 2016 10:56:03 +0200 Subject: [PATCH] gpio: flush direction status in gpiochip_lock_as_irq() As irqchip and gpiochip functions are orthogonal, the IRQ set-up or something else can have changed the direction of the GPIO line from what the GPIO descriptor knows when we get into gpiochip_lock_as_irq(). Make sure to re-read the direction setting if we have the .get_direction() callback enabled for the chip. Else we get problems like this: iio iio:device2: interrupts on the rising edge gpio gpiochip2: (8012e080.gpio): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ gpio gpiochip2: (8012e080.gpio): unable to lock HW IRQ 0 for IRQ genirq: Failed to request resources for l3g4200d-trigger (irq 111) on irqchip nmk1-32-63 iio iio:device2: failed to request trigger IRQ. st-gyro-i2c: probe of 2-0068 failed with error -22 Fixes: 72d320006177 ("gpio: set up initial state from .get_direction()") Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d407f904a31c..e901d2666b46 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2066,17 +2066,30 @@ EXPORT_SYMBOL_GPL(gpiod_to_irq); */ int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) { - if (offset >= chip->ngpio) - return -EINVAL; + struct gpio_desc *desc; + + desc = gpiochip_get_desc(chip, offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + /* Flush direction if something changed behind our back */ + if (chip->get_direction) { + int dir = chip->get_direction(chip, offset); + + if (dir) + clear_bit(FLAG_IS_OUT, &desc->flags); + else + set_bit(FLAG_IS_OUT, &desc->flags); + } - if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) { + if (test_bit(FLAG_IS_OUT, &desc->flags)) { chip_err(chip, "%s: tried to flag a GPIO set as output for IRQ\n", __func__); return -EIO; } - set_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags); + set_bit(FLAG_USED_AS_IRQ, &desc->flags); return 0; } EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); -- 2.20.1