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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2018-07-02 23:05:21 +0300
committerJacek Anaszewski <jacek.anaszewski@gmail.com>2018-07-06 00:21:10 +0300
commit2282e125a406e09331c5a785e3df29035c99a607 (patch)
treeb5936ee2bde7c85bf71aaff259026857b2bda6d9 /drivers/leds/led-triggers.c
parent033692eb3ec8305f6e9998b297aaec6899680637 (diff)
downloadlinux-2282e125a406e09331c5a785e3df29035c99a607.tar.xz
leds: triggers: let struct led_trigger::activate() return an error code
Given that activating a trigger can fail, let the callback return an indication. This prevents to have a trigger active according to the "trigger" sysfs attribute but not functional. All users are changed accordingly to return 0 for now. There is no intended change in behaviour. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Diffstat (limited to 'drivers/leds/led-triggers.c')
-rw-r--r--drivers/leds/led-triggers.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 431123b048a2..a8786f4b3453 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -103,15 +103,16 @@ ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
EXPORT_SYMBOL_GPL(led_trigger_show);
/* Caller must ensure led_cdev->trigger_lock held */
-void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
+int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
{
unsigned long flags;
char *event = NULL;
char *envp[2];
const char *name;
+ int ret;
if (!led_cdev->trigger && !trig)
- return;
+ return 0;
name = trig ? trig->name : "none";
event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
@@ -134,8 +135,14 @@ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
write_unlock_irqrestore(&trig->leddev_list_lock, flags);
led_cdev->trigger = trig;
+
if (trig->activate)
- trig->activate(led_cdev);
+ ret = trig->activate(led_cdev);
+ else
+ ret = 0;
+
+ if (ret)
+ goto err_activate;
}
if (event) {
@@ -146,6 +153,17 @@ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
"%s: Error sending uevent\n", __func__);
kfree(event);
}
+
+ return 0;
+
+err_activate:
+ led_cdev->trigger = NULL;
+ write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
+ list_del(&led_cdev->trig_list);
+ write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
+ led_set_brightness(led_cdev, LED_OFF);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(led_trigger_set);