fixed awkward locking bug for video event queue

2 files changed, 7 insertions, 9 deletions

diff --git a/linux/drivers/media/dvb/ttpci/av7110.c b/linux/drivers/media/dvb/ttpci/av7110.c
index c0af67c34..22391bd9f 100644
--- a/linux/drivers/media/dvb/ttpci/av7110.c
+++ b/linux/drivers/media/dvb/ttpci/av7110.c
@@ -3365,8 +3365,7 @@ void dvb_video_add_event (av7110_t *av7110, struct video_event *event)
 
 	DEB_D(("\n"));
 
-	if (down_interruptible (&events->sem))
-		return;
+	spin_lock_bh(&events->lock);
 
 	wp = (events->eventw + 1) % MAX_VIDEO_EVENT;
 
@@ -3380,7 +3379,7 @@ void dvb_video_add_event (av7110_t *av7110, struct video_event *event)
 
 	events->eventw = wp;
 
-	up (&events->sem);
+	spin_unlock_bh(&events->lock);
 
 	wake_up_interruptible (&events->wait_queue);
 }
@@ -3410,15 +3409,14 @@ int dvb_video_get_event (av7110_t *av7110, struct video_event *event, int flags)
                         return ret;
         }
 
-        if (down_interruptible (&events->sem))
-		return -ERESTARTSYS;
+	spin_lock_bh(&events->lock);
 
 	memcpy (event, &events->events[events->eventr],
 		sizeof(struct video_event));
 
         events->eventr = (events->eventr + 1) % MAX_VIDEO_EVENT;
 
-	up (&events->sem);
+	spin_unlock_bh(&events->lock);
 
         return 0;
 }
@@ -4049,8 +4047,8 @@ int av7110_register(av7110_t *av7110)
         if (ret < 0)
                 return ret;
 
-	init_waitqueue_head (&av7110->video_events.wait_queue);
-	init_MUTEX (&av7110->video_events.sem);
+	init_waitqueue_head(&av7110->video_events.wait_queue);
+	spin_lock_init(&av7110->video_events.lock);
 	av7110->video_events.eventw = av7110->video_events.eventr = 0;
 	av7110->video_events.overflow = 0;
 	memset(&av7110->video_size, 0, sizeof (video_size_t));
diff --git a/linux/drivers/media/dvb/ttpci/av7110.h b/linux/drivers/media/dvb/ttpci/av7110.h
index b9d2fc995..0128ba102 100644
--- a/linux/drivers/media/dvb/ttpci/av7110.h
+++ b/linux/drivers/media/dvb/ttpci/av7110.h
@@ -456,7 +456,7 @@ struct dvb_video_events {
 	int                       eventr;
 	int                       overflow;
 	wait_queue_head_t         wait_queue;
-	struct semaphore          sem;
+	spinlock_t                lock;
 };