Commit 8636f19c authored by Alexander Sverdlin's avatar Alexander Sverdlin Committed by Bartosz Golaszewski
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gpio: sysfs: repair export returning -EPERM on 1st attempt 



It would make sense to return -EPERM if the bit was already set (already
used), not if it was cleared. Before this fix pins can only be exported on
the 2nd attempt:

$ echo 522 > /sys/class/gpio/export
sh: write error: Operation not permitted
$ echo 522 > /sys/class/gpio/export

Fixes: 35b54533 ("gpio: remove gpio_lock")
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 297dc37a

drivers/gpio/gpiolib-sysfs.c

+1 −1
Original line number Diff line number Diff line
@@ -593,7 +593,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) 
	if (!guard.gc)

		return -ENODEV;



	if (!test_and_set_bit(FLAG_EXPORT, &desc->flags))

	if (test_and_set_bit(FLAG_EXPORT, &desc->flags))

		return -EPERM;



	gdev = desc->gdev;