gpiolib: Preserve desc->flags when setting state

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

Cc: stable@vger.kernel.org
Fixes: 3edfb7bd76bd1cba ("gpiolib: Show correct direction from the beginning")
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20190707203558.10993-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index bf05c29b53be925110c7d4179af277dc403713fc..f497003f119c993a55e18ac0c54fcf95c138a2be 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1394,12 +1394,17 @@ 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);