[PATCH v3] gpiolib: Preserve desc->flags when setting state

From: Chris Packham
Date: Sun Jul 07 2019 - 16:36:30 EST


desc->flags may already have values set by of_gpiochip_add() so make
sure that this isn't undone when setting the initial direction.

Fixes: 3edfb7bd76bd1cba ("gpiolib: Show correct direction from the beginning")
Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
---

Notes:
Changes in v2:
- add braces to avoid ambiguious else warning
Changes in v3:
- clear the direction output in the negative case

drivers/gpio/gpiolib.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e013d417a936..dbd1180316a0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1392,12 +1392,17 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
for (i = 0; i < chip->ngpio; i++) {
struct gpio_desc *desc = &gdev->descs[i];

- if (chip->get_direction && gpiochip_line_is_valid(chip, i))
- desc->flags = !chip->get_direction(chip, i) ?
- (1 << FLAG_IS_OUT) : 0;
- else
- desc->flags = !chip->direction_input ?
- (1 << FLAG_IS_OUT) : 0;
+ if (chip->get_direction && gpiochip_line_is_valid(chip, i)) {
+ if (!chip->get_direction(chip, i))
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ else
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ } else {
+ if (!chip->direction_input)
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ else
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ }
}

acpi_gpiochip_add(chip);
--
2.22.0