From 2282e125a406e09331c5a785e3df29035c99a607 Mon Sep 17 00:00:00 2001 From: Uwe Kleine-König Date: Mon, 2 Jul 2018 22:05:21 +0200 Subject: leds: triggers: let struct led_trigger::activate() return an error code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Pavel Machek Signed-off-by: Jacek Anaszewski --- drivers/leds/led-triggers.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) (limited to 'drivers/leds/led-triggers.c') 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); -- cgit v1.2.3