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-rw-r--r--drivers/media/video/videobuf-core.c96
-rw-r--r--include/media/videobuf-core.h2
2 files changed, 78 insertions, 20 deletions
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index 1ba3aaa29dd..3ab556093ca 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -141,6 +141,7 @@ void videobuf_queue_core_init(struct videobuf_queue *q,
BUG_ON(!q->int_ops);
mutex_init(&q->vb_lock);
+ init_waitqueue_head(&q->wait);
INIT_LIST_HEAD(&q->stream);
}
@@ -188,6 +189,10 @@ void videobuf_queue_cancel(struct videobuf_queue *q)
unsigned long flags = 0;
int i;
+ q->streaming = 0;
+ q->reading = 0;
+ wake_up_interruptible_sync(&q->wait);
+
/* remove queued buffers from list */
if (q->irqlock)
spin_lock_irqsave(q->irqlock, flags);
@@ -565,6 +570,7 @@ int videobuf_qbuf(struct videobuf_queue *q,
}
dprintk(1, "qbuf: succeded\n");
retval = 0;
+ wake_up_interruptible_sync(&q->wait);
done:
mutex_unlock(&q->vb_lock);
@@ -575,37 +581,88 @@ int videobuf_qbuf(struct videobuf_queue *q,
return retval;
}
-int videobuf_dqbuf(struct videobuf_queue *q,
- struct v4l2_buffer *b, int nonblocking)
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
{
- struct videobuf_buffer *buf;
int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
-
- mutex_lock(&q->vb_lock);
- retval = -EBUSY;
- if (q->reading) {
- dprintk(1, "dqbuf: Reading running...\n");
- goto done;
- }
- retval = -EINVAL;
- if (b->type != q->type) {
- dprintk(1, "dqbuf: Wrong type.\n");
+checks:
+ if (!q->streaming) {
+ dprintk(1, "next_buffer: Not streaming\n");
+ retval = -EINVAL;
goto done;
}
+
if (list_empty(&q->stream)) {
- dprintk(1, "dqbuf: stream running\n");
- goto done;
+ if (noblock) {
+ retval = -EAGAIN;
+ dprintk(2, "next_buffer: no buffers to dequeue\n");
+ goto done;
+ } else {
+ dprintk(2, "next_buffer: waiting on buffer\n");
+
+ /* Drop lock to avoid deadlock with qbuf */
+ mutex_unlock(&q->vb_lock);
+
+ /* Checking list_empty and streaming is safe without
+ * locks because we goto checks to validate while
+ * holding locks before proceeding */
+ retval = wait_event_interruptible(q->wait,
+ !list_empty(&q->stream) || !q->streaming);
+ mutex_lock(&q->vb_lock);
+
+ if (retval)
+ goto done;
+
+ goto checks;
+ }
}
+
+ retval = 0;
+
+done:
+ return retval;
+}
+
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer(struct videobuf_queue *q,
+ struct videobuf_buffer **vb, int nonblocking)
+{
+ int retval;
+ struct videobuf_buffer *buf = NULL;
+
+ retval = stream_next_buffer_check_queue(q, nonblocking);
+ if (retval)
+ goto done;
+
buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
- mutex_unlock(&q->vb_lock);
retval = videobuf_waiton(buf, nonblocking, 1);
+ if (retval < 0)
+ goto done;
+
+ *vb = buf;
+done:
+ return retval;
+}
+
+int videobuf_dqbuf(struct videobuf_queue *q,
+ struct v4l2_buffer *b, int nonblocking)
+{
+ struct videobuf_buffer *buf = NULL;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
mutex_lock(&q->vb_lock);
+
+ retval = stream_next_buffer(q, &buf, nonblocking);
if (retval < 0) {
- dprintk(1, "dqbuf: waiton returned %d\n", retval);
+ dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
goto done;
}
+
switch (buf->state) {
case VIDEOBUF_ERROR:
dprintk(1, "dqbuf: state is error\n");
@@ -654,6 +711,7 @@ int videobuf_streamon(struct videobuf_queue *q)
if (q->irqlock)
spin_unlock_irqrestore(q->irqlock, flags);
+ wake_up_interruptible_sync(&q->wait);
done:
mutex_unlock(&q->vb_lock);
return retval;
@@ -666,7 +724,6 @@ static int __videobuf_streamoff(struct videobuf_queue *q)
return -EINVAL;
videobuf_queue_cancel(q);
- q->streaming = 0;
return 0;
}
@@ -869,7 +926,6 @@ static void __videobuf_read_stop(struct videobuf_queue *q)
q->bufs[i] = NULL;
}
q->read_buf = NULL;
- q->reading = 0;
}
diff --git a/include/media/videobuf-core.h b/include/media/videobuf-core.h
index fcdffdd6330..377a6c6e931 100644
--- a/include/media/videobuf-core.h
+++ b/include/media/videobuf-core.h
@@ -153,6 +153,8 @@ struct videobuf_queue {
spinlock_t *irqlock;
struct device *dev;
+ wait_queue_head_t wait; /* wait if queue is empty */
+
enum v4l2_buf_type type;
unsigned int inputs; /* for V4L2_BUF_FLAG_INPUT */
unsigned int msize;