1 files changed, 46 insertions, 24 deletions

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 7ae605f6bbb6..e78ddbe5a954 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -601,24 +601,41 @@ static struct attribute *comedi_dev_attrs[] = {
 };
 ATTRIBUTE_GROUPS(comedi_dev);
 
+static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s,
+					      unsigned bits)
+{
+	s->runflags &= ~bits;
+}
+
+static void __comedi_set_subdevice_runflags(struct comedi_subdevice *s,
+					    unsigned bits)
+{
+	s->runflags |= bits;
+}
+
 static void comedi_update_subdevice_runflags(struct comedi_subdevice *s,
 					     unsigned mask, unsigned bits)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&s->spin_lock, flags);
-	s->runflags &= ~mask;
-	s->runflags |= (bits & mask);
+	__comedi_clear_subdevice_runflags(s, mask);
+	__comedi_set_subdevice_runflags(s, bits & mask);
 	spin_unlock_irqrestore(&s->spin_lock, flags);
 }
 
+static unsigned __comedi_get_subdevice_runflags(struct comedi_subdevice *s)
+{
+	return s->runflags;
+}
+
 static unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s)
 {
 	unsigned long flags;
 	unsigned runflags;
 
 	spin_lock_irqsave(&s->spin_lock, flags);
-	runflags = s->runflags;
+	runflags = __comedi_get_subdevice_runflags(s);
 	spin_unlock_irqrestore(&s->spin_lock, flags);
 	return runflags;
 }
@@ -648,6 +665,13 @@ bool comedi_is_subdevice_running(struct comedi_subdevice *s)
 }
 EXPORT_SYMBOL_GPL(comedi_is_subdevice_running);
 
+static bool __comedi_is_subdevice_running(struct comedi_subdevice *s)
+{
+	unsigned runflags = __comedi_get_subdevice_runflags(s);
+
+	return comedi_is_runflags_running(runflags);
+}
+
 static bool comedi_is_subdevice_idle(struct comedi_subdevice *s)
 {
 	unsigned runflags = comedi_get_subdevice_runflags(s);
@@ -2646,40 +2670,38 @@ static const struct file_operations comedi_fops = {
 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
 {
 	struct comedi_async *async = s->async;
-	unsigned runflags = 0;
-	unsigned runflags_mask = 0;
-	unsigned int events = async->events;
+	unsigned int events;
+	int si_code = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->spin_lock, flags);
 
+	events = async->events;
 	async->events = 0;
-	if (!comedi_is_subdevice_running(s))
+	if (!__comedi_is_subdevice_running(s)) {
+		spin_unlock_irqrestore(&s->spin_lock, flags);
 		return;
+	}
 
 	if (events & COMEDI_CB_CANCEL_MASK)
-		runflags_mask |= COMEDI_SRF_RUNNING;
+		__comedi_clear_subdevice_runflags(s, COMEDI_SRF_RUNNING);
 
 	/*
-	 * Remember if an error event has occurred, so an error
-	 * can be returned the next time the user does a read().
+	 * Remember if an error event has occurred, so an error can be
+	 * returned the next time the user does a read() or write().
 	 */
-	if (events & COMEDI_CB_ERROR_MASK) {
-		runflags_mask |= COMEDI_SRF_ERROR;
-		runflags |= COMEDI_SRF_ERROR;
-	}
-	if (runflags_mask) {
-		/*
-		 * Changes COMEDI_SRF_ERROR and COMEDI_SRF_RUNNING together
-		 * atomically.
-		 */
-		comedi_update_subdevice_runflags(s, runflags_mask, runflags);
-	}
+	if (events & COMEDI_CB_ERROR_MASK)
+		__comedi_set_subdevice_runflags(s, COMEDI_SRF_ERROR);
 
 	if (async->cb_mask & events) {
-		int si_code;
-
 		wake_up_interruptible(&async->wait_head);
 		si_code = async->cmd.flags & CMDF_WRITE ? POLL_OUT : POLL_IN;
-		kill_fasync(&dev->async_queue, SIGIO, si_code);
 	}
+
+	spin_unlock_irqrestore(&s->spin_lock, flags);
+
+	if (si_code)
+		kill_fasync(&dev->async_queue, SIGIO, si_code);
 }
 EXPORT_SYMBOL_GPL(comedi_event);