V4L/DVB (8772): cx18: Convert cx18_queue buffers member to atomic_t
cx18: Convert cx18_queue buffers member to atomic_t. This allows safe
concurrent access to check if a queue has data without having to acquire the
queue spinlock.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/cx18/cx18-queue.c b/drivers/media/video/cx18/cx18-queue.c
index 4f3bd43..a33ba04 100644
--- a/drivers/media/video/cx18/cx18-queue.c
+++ b/drivers/media/video/cx18/cx18-queue.c
@@ -37,7 +37,7 @@
void cx18_queue_init(struct cx18_queue *q)
{
INIT_LIST_HEAD(&q->list);
- q->buffers = 0;
+ atomic_set(&q->buffers, 0);
q->bytesused = 0;
}
@@ -54,7 +54,7 @@
}
spin_lock_irqsave(&s->qlock, flags);
list_add_tail(&buf->list, &q->list);
- q->buffers++;
+ atomic_inc(&q->buffers);
q->bytesused += buf->bytesused - buf->readpos;
spin_unlock_irqrestore(&s->qlock, flags);
}
@@ -68,7 +68,7 @@
if (!list_empty(&q->list)) {
buf = list_entry(q->list.next, struct cx18_buffer, list);
list_del_init(q->list.next);
- q->buffers--;
+ atomic_dec(&q->buffers);
q->bytesused -= buf->bytesused - buf->readpos;
}
spin_unlock_irqrestore(&s->qlock, flags);
@@ -92,8 +92,8 @@
/* the transport buffers are handled differently,
they are not moved to the full queue */
if (s->type != CX18_ENC_STREAM_TYPE_TS) {
- s->q_free.buffers--;
- s->q_full.buffers++;
+ atomic_dec(&s->q_free.buffers);
+ atomic_inc(&s->q_full.buffers);
s->q_full.bytesused += buf->bytesused;
list_move_tail(&buf->list, &s->q_full.list);
}
@@ -119,7 +119,7 @@
buf = list_entry(q->list.next, struct cx18_buffer, list);
list_move_tail(q->list.next, &s->q_free.list);
buf->bytesused = buf->readpos = buf->b_flags = 0;
- s->q_free.buffers++;
+ atomic_inc(&s->q_free.buffers);
}
cx18_queue_init(q);
spin_unlock_irqrestore(&s->qlock, flags);