diff options
Diffstat (limited to 'drivers/rtc/interface.c')
| -rw-r--r-- | drivers/rtc/interface.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index ad66c6ecf36..a43afa54f0d 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -210,6 +210,10 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) if (task == NULL || task->func == NULL) return -EINVAL; + /* Cannot register while the char dev is in use */ + if (!(mutex_trylock(&rtc->char_lock))) + return -EBUSY; + spin_lock_irq(&rtc->irq_task_lock); if (rtc->irq_task == NULL) { rtc->irq_task = task; @@ -217,13 +221,14 @@ int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) } spin_unlock_irq(&rtc->irq_task_lock); + mutex_unlock(&rtc->char_lock); + return retval; } EXPORT_SYMBOL_GPL(rtc_irq_register); void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) { - spin_lock_irq(&rtc->irq_task_lock); if (rtc->irq_task == task) rtc->irq_task = NULL; @@ -240,8 +245,10 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled return -ENXIO; spin_lock_irqsave(&rtc->irq_task_lock, flags); + if (rtc->irq_task != NULL && task == NULL) + err = -EBUSY; if (rtc->irq_task != task) - err = -ENXIO; + err = -EACCES; spin_unlock_irqrestore(&rtc->irq_task_lock, flags); if (err == 0) @@ -260,8 +267,10 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) return -ENXIO; spin_lock_irqsave(&rtc->irq_task_lock, flags); + if (rtc->irq_task != NULL && task == NULL) + err = -EBUSY; if (rtc->irq_task != task) - err = -ENXIO; + err = -EACCES; spin_unlock_irqrestore(&rtc->irq_task_lock, flags); if (err == 0) { |