[PATCH v1 1/1] gpiolib: sysfs: Do unexport GPIO when user asks for it

From: Andy Shevchenko
Date: Mon Aug 14 2023 - 07:20:35 EST


It seems that sysfs interface implicitly relied on the gpiod_free()
to unexport the line. This is not good and prone to regressions.
Fix it by explicitly calling gpiod_unexport().

Fixes: b0ce9ce408b6 ("gpiolib: Do not unexport GPIO on freeing")
Reported-by: Marek Behún <kabel@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/20230808102828.4a9eac09@dellmb
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Tested-by: Marek Behún <kabel@xxxxxxxxxx>
---
drivers/gpio/gpiolib-sysfs.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 530dfd19d7b5..50503a4525eb 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -515,8 +515,9 @@ static ssize_t unexport_store(const struct class *class,
* they may be undone on its behalf too.
*/
if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
+ gpiod_unexport(desc);
+ gpiod_free(desc);
status = 0;
- gpiod_free(desc);
}
done:
if (status)
@@ -781,8 +782,10 @@ void gpiochip_sysfs_unregister(struct gpio_device *gdev)
mutex_unlock(&sysfs_lock);

/* unregister gpiod class devices owned by sysfs */
- for_each_gpio_desc_with_flag(chip, desc, FLAG_SYSFS)
+ for_each_gpio_desc_with_flag(chip, desc, FLAG_SYSFS) {
+ gpiod_unexport(desc);
gpiod_free(desc);
+ }
}

static int __init gpiolib_sysfs_init(void)
--
2.40.0.1.gaa8946217a0b