gpio: sysfs: only get the dirent reference for the value attr once

There's no reason to retrieve the reference to the sysfs dirent every
time we request an interrupt, we can as well only do it once when
exporting the GPIO.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250704-gpio-sysfs-chip-export-v4-3-9289d8758243@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 990db0405cc86c42bad61295dc823f970199534e..39e9ca31f034e20abd08fb5e9b4eecf24f127d5e 100644 (file)
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -177,10 +177,6 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
        if (data->irq < 0)
                return -EIO;
 
-       data->value_kn = sysfs_get_dirent(dev->kobj.sd, "value");
-       if (!data->value_kn)
-               return -ENODEV;
-
        irq_flags = IRQF_SHARED;
        if (flags & GPIO_IRQF_TRIGGER_FALLING) {
                irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
@@ -203,7 +199,7 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
         */
        ret = gpiochip_lock_as_irq(guard.gc, gpio_chip_hwgpio(desc));
        if (ret < 0)
-               goto err_put_kn;
+               goto err_clr_bits;
 
        ret = request_any_context_irq(data->irq, gpio_sysfs_irq, irq_flags,
                                "gpiolib", data);
@@ -216,10 +212,9 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
 
 err_unlock:
        gpiochip_unlock_as_irq(guard.gc, gpio_chip_hwgpio(desc));
-err_put_kn:
+err_clr_bits:
        clear_bit(FLAG_EDGE_RISING, &desc->flags);
        clear_bit(FLAG_EDGE_FALLING, &desc->flags);
-       sysfs_put(data->value_kn);
 
        return ret;
 }
@@ -242,7 +237,6 @@ static void gpio_sysfs_free_irq(struct device *dev)
        gpiochip_unlock_as_irq(guard.gc, gpio_chip_hwgpio(desc));
        clear_bit(FLAG_EDGE_RISING, &desc->flags);
        clear_bit(FLAG_EDGE_FALLING, &desc->flags);
-       sysfs_put(data->value_kn);
 }
 
 static const char *const trigger_names[] = {
@@ -726,8 +720,16 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
                goto err_free_data;
        }
 
+       data->value_kn = sysfs_get_dirent(dev->kobj.sd, "value");
+       if (!data->value_kn) {
+               status = -ENODEV;
+               goto err_unregister_device;
+       }
+
        return 0;
 
+err_unregister_device:
+       device_unregister(dev);
 err_free_data:
        kfree(data);
 err_clear_bit:
@@ -804,6 +806,7 @@ void gpiod_unexport(struct gpio_desc *desc)
 
                data = dev_get_drvdata(dev);
                clear_bit(FLAG_EXPORT, &desc->flags);
+               sysfs_put(data->value_kn);
                device_unregister(dev);
 
                /*