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: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 10ab3b7..4dfdf01 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -153,6 +153,7 @@
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);
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index ad66c6e..a43afa5 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -210,6 +210,10 @@
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 @@
}
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 @@
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 @@
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) {
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 005fff3..362400d 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -238,17 +238,6 @@
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 @@
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 @@
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);