Commit d691eb90 authored by Alessandro Zummo's avatar Alessandro Zummo Committed by Linus Torvalds

RTC: periodic irq fix

Add kernel/kernel and kernel/user locking for the periodic irq feature of
the rtc class.

PIE ioctls are also supported.
Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 16a72c45
......@@ -153,6 +153,7 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev,
mutex_init(&rtc->ops_lock);
spin_lock_init(&rtc->irq_lock);
spin_lock_init(&rtc->irq_task_lock);
init_waitqueue_head(&rtc->irq_queue);
strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
snprintf(rtc->dev.bus_id, BUS_ID_SIZE, "rtc%d", id);
......
......@@ -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) {
......
......@@ -238,17 +238,6 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
break;
}
/* avoid conflicting IRQ users */
if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
spin_lock_irq(&rtc->irq_task_lock);
if (rtc->irq_task)
err = -EBUSY;
spin_unlock_irq(&rtc->irq_task_lock);
if (err < 0)
return err;
}
/* try the driver's ioctl interface */
if (ops->ioctl) {
err = ops->ioctl(rtc->dev.parent, cmd, arg);
......@@ -338,18 +327,20 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
err = rtc_set_time(rtc, &tm);
break;
case RTC_IRQP_READ:
if (ops->irq_set_freq)
err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
else
err = -ENOTTY;
case RTC_PIE_ON:
err = rtc_irq_set_state(rtc, NULL, 1);
break;
case RTC_PIE_OFF:
err = rtc_irq_set_state(rtc, NULL, 0);
break;
case RTC_IRQP_SET:
if (ops->irq_set_freq)
err = rtc_irq_set_freq(rtc, rtc->irq_task, arg);
else
err = -ENOTTY;
err = rtc_irq_set_freq(rtc, NULL, arg);
break;
case RTC_IRQP_READ:
err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
break;
#if 0
......@@ -449,8 +440,6 @@ void rtc_dev_prepare(struct rtc_device *rtc)
rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
mutex_init(&rtc->char_lock);
spin_lock_init(&rtc->irq_lock);
init_waitqueue_head(&rtc->irq_queue);
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
INIT_WORK(&rtc->uie_task, rtc_uie_task);
setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
......
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