int videobuf_read_start(struct videobuf_queue *q)
{
int rc;
mutex_lock(&q->lock);
rc = __videobuf_read_start(q);
mutex_unlock(&q->lock);
return rc;
}
int videobuf_read_start(struct videobuf_queue *q)
{
int rc;
videobuf_queue_lock(q);
rc = __videobuf_read_start(q);
videobuf_queue_unlock(q);
return rc;
}
ssize_t videobuf_read_stream(struct videobuf_queue *q,
char __user *data, size_t count, loff_t *ppos,
int vbihack, int nonblocking)
{
int rc, retval;
unsigned long flags=0;
MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS);
dprintk(2,"%s\n",__FUNCTION__);
mutex_lock(&q->lock);
retval = -EBUSY;
if (q->streaming)
goto done;
if (!q->reading) {
retval = __videobuf_read_start(q);
if (retval < 0)
goto done;
}
retval = 0;
while (count > 0) {
/* get / wait for data */
if (NULL == q->read_buf) {
q->read_buf = list_entry(q->stream.next,
struct videobuf_buffer,
stream);
list_del(&q->read_buf->stream);
q->read_off = 0;
}
rc = videobuf_waiton(q->read_buf, nonblocking, 1);
if (rc < 0) {
if (0 == retval)
retval = rc;
break;
}
if (q->read_buf->state == STATE_DONE) {
rc = CALL (q,copy_stream, q, data + retval, count,
retval, vbihack, nonblocking);
if (rc < 0) {
retval = rc;
break;
}
retval += rc;
count -= rc;
q->read_off += rc;
} else {
/* some error */
q->read_off = q->read_buf->size;
if (0 == retval)
retval = -EIO;
}
/* requeue buffer when done with copying */
if (q->read_off == q->read_buf->size) {
list_add_tail(&q->read_buf->stream,
&q->stream);
if (q->irqlock)
spin_lock_irqsave(q->irqlock,flags);
q->ops->buf_queue(q,q->read_buf);
if (q->irqlock)
spin_unlock_irqrestore(q->irqlock,flags);
q->read_buf = NULL;
}
if (retval < 0)
break;
}