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| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2018-07-02 22:05:21 +0200 |
|---|---|---|
| committer | Jacek Anaszewski <jacek.anaszewski@gmail.com> | 2018-07-05 23:21:10 +0200 |
| commit | 2282e125a406e09331c5a785e3df29035c99a607 (patch) | |
| tree | b5936ee2bde7c85bf71aaff259026857b2bda6d9 /drivers/leds/led-triggers.c | |
| parent | 033692eb3ec8305f6e9998b297aaec6899680637 (diff) | |
| download | lwn-2282e125a406e09331c5a785e3df29035c99a607.tar.gz lwn-2282e125a406e09331c5a785e3df29035c99a607.zip | |
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.c | 24 |
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); |