diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2016-05-25 11:56:03 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2016-05-30 10:42:03 +0300 |
| commit | 9c10280d85c14a20751ab6c1185ad725172936d6 (patch) | |
| tree | f72f8ad76edba5852dd72714dfd0bf8a5ac3bd8c /drivers | |
| parent | 320a6480ef24b03655e1854bd01c9b0a8b8d4a3f (diff) | |
| download | linux-9c10280d85c14a20751ab6c1185ad725172936d6.tar.xz | |
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 <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 21 |
1 files 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); |