/* Locking: Caller holds q->vb_lock */
static int __videobuf_read_start(struct videobuf_queue *q)
{
enum v4l2_field field;
unsigned long flags = 0;
unsigned int count = 0, size = 0;
int err, i;
q->ops->buf_setup(q, &count, &size);
if (count < 2)
count = 2;
if (count > VIDEO_MAX_FRAME)
count = VIDEO_MAX_FRAME;
size = PAGE_ALIGN(size);
err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
if (err < 0)
return err;
count = err;
for (i = 0; i < count; i++) {
field = videobuf_next_field(q);
err = q->ops->buf_prepare(q, q->bufs[i], field);
if (err)
return err;
list_add_tail(&q->bufs[i]->stream, &q->stream);
}
spin_lock_irqsave(q->irqlock, flags);
for (i = 0; i < count; i++)
q->ops->buf_queue(q, q->bufs[i]);
spin_unlock_irqrestore(q->irqlock, flags);
q->reading = 1;
return 0;
}
int videobuf_reqbufs(struct videobuf_queue *q,
struct v4l2_requestbuffers *req)
{
unsigned int size, count;
int retval;
if (req->memory != V4L2_MEMORY_MMAP &&
req->memory != V4L2_MEMORY_USERPTR &&
req->memory != V4L2_MEMORY_OVERLAY) {
dprintk(1, "reqbufs: memory type invalid\n");
return -EINVAL;
}
videobuf_queue_lock(q);
if (req->type != q->type) {
dprintk(1, "reqbufs: queue type invalid\n");
retval = -EINVAL;
goto done;
}
if (q->streaming) {
dprintk(1, "reqbufs: streaming already exists\n");
retval = -EBUSY;
goto done;
}
if (!list_empty(&q->stream)) {
dprintk(1, "reqbufs: stream running\n");
retval = -EBUSY;
goto done;
}
if (req->count == 0) {
dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
retval = __videobuf_free(q);
goto done;
}
count = req->count;
if (count > VIDEO_MAX_FRAME)
count = VIDEO_MAX_FRAME;
size = 0;
q->ops->buf_setup(q, &count, &size);
dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
count, size,
(unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
retval = __videobuf_mmap_setup(q, count, size, req->memory);
if (retval < 0) {
dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
goto done;
}
req->count = retval;
retval = 0;
done:
videobuf_queue_unlock(q);
return retval;
}
int videobuf_mmap_setup(struct videobuf_queue *q,
unsigned int bcount, unsigned int bsize,
enum v4l2_memory memory)
{
int ret;
mutex_lock(&q->lock);
ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
mutex_unlock(&q->lock);
return ret;
}
