* Make sure the requested values and current defaults are sane.
*/
num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
+ num_buffers = max_t(unsigned int, req->count, q->min_buffers_needed);
memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
q->memory = req->memory;
allocated_buffers = ret;
/*
+ * There is no point in continuing if we can't allocate the minimum
+ * number of buffers needed by this vb2_queue.
+ */
+ if (allocated_buffers < q->min_buffers_needed)
+ ret = -ENOMEM;
+
+ /*
* Check if driver can handle the allocated number of buffers.
*/
- if (allocated_buffers < num_buffers) {
+ if (!ret && allocated_buffers < num_buffers) {
num_buffers = allocated_buffers;
ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
* to the userspace.
*/
req->count = allocated_buffers;
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
return 0;
}
memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
q->memory = create->memory;
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
}
num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
* vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
* @vb: vb2_buffer returned from the driver
* @state: either VB2_BUF_STATE_DONE if the operation finished successfully
- * or VB2_BUF_STATE_ERROR if the operation finished with an error
+ * or VB2_BUF_STATE_ERROR if the operation finished with an error.
+ * If start_streaming fails then it should return buffers with state
+ * VB2_BUF_STATE_QUEUED to put them back into the queue.
*
* This function should be called by the driver after a hardware operation on
* a buffer is finished and the buffer may be returned to userspace. The driver
* cannot use this buffer anymore until it is queued back to it by videobuf
* by the means of buf_queue callback. Only buffers previously queued to the
* driver by buf_queue can be passed to this function.
+ *
+ * While streaming a buffer can only be returned in state DONE or ERROR.
+ * The start_streaming op can also return them in case the DMA engine cannot
+ * be started for some reason. In that case the buffers should be returned with
+ * state QUEUED.
*/
void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
{
unsigned long flags;
unsigned int plane;
- if (vb->state != VB2_BUF_STATE_ACTIVE)
+ if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
return;
- if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
- return;
+ if (!q->start_streaming_called) {
+ if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
+ state = VB2_BUF_STATE_QUEUED;
+ } else if (!WARN_ON(!q->start_streaming_called)) {
+ if (WARN_ON(state != VB2_BUF_STATE_DONE &&
+ state != VB2_BUF_STATE_ERROR))
+ state = VB2_BUF_STATE_ERROR;
+ }
dprintk(4, "Done processing on buffer %d, state: %d\n",
vb->v4l2_buf.index, state);
/* Add the buffer to the done buffers list */
spin_lock_irqsave(&q->done_lock, flags);
vb->state = state;
- list_add_tail(&vb->done_entry, &q->done_list);
- atomic_dec(&q->queued_count);
+ if (state != VB2_BUF_STATE_QUEUED)
+ list_add_tail(&vb->done_entry, &q->done_list);
+ atomic_dec(&q->owned_by_drv_count);
spin_unlock_irqrestore(&q->done_lock, flags);
+ if (state == VB2_BUF_STATE_QUEUED)
+ return;
+
/* Inform any processes that may be waiting for buffers */
wake_up(&q->done_wq);
}
unsigned int plane;
vb->state = VB2_BUF_STATE_ACTIVE;
- atomic_inc(&q->queued_count);
+ atomic_inc(&q->owned_by_drv_count);
/* sync buffers */
for (plane = 0; plane < vb->num_planes; ++plane)
* vb2_start_streaming() - Attempt to start streaming.
* @q: videobuf2 queue
*
- * If there are not enough buffers, then retry_start_streaming is set to
- * 1 and 0 is returned. The next time a buffer is queued and
- * retry_start_streaming is 1, this function will be called again to
- * retry starting the DMA engine.
+ * Attempt to start streaming. When this function is called there must be
+ * at least q->min_buffers_needed buffers queued up (i.e. the minimum
+ * number of buffers required for the DMA engine to function). If the
+ * @start_streaming op fails it is supposed to return all the driver-owned
+ * buffers back to vb2 in state QUEUED. Check if that happened and if
+ * not warn and reclaim them forcefully.
*/
static int vb2_start_streaming(struct vb2_queue *q)
{
+ struct vb2_buffer *vb;
int ret;
- /* Tell the driver to start streaming */
- ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
-
/*
- * If there are not enough buffers queued to start streaming, then
- * the start_streaming operation will return -ENOBUFS and you have to
- * retry when the next buffer is queued.
+ * If any buffers were queued before streamon,
+ * we can now pass them to driver for processing.
*/
- if (ret == -ENOBUFS) {
- dprintk(1, "qbuf: not enough buffers, retry when more buffers are queued.\n");
- q->retry_start_streaming = 1;
+ list_for_each_entry(vb, &q->queued_list, queued_entry)
+ __enqueue_in_driver(vb);
+
+ /* Tell the driver to start streaming */
+ q->start_streaming_called = 1;
+ ret = call_qop(q, start_streaming, q,
+ atomic_read(&q->owned_by_drv_count));
+ if (!ret)
return 0;
+
+ q->start_streaming_called = 0;
+
+ dprintk(1, "qbuf: driver refused to start streaming\n");
+ if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
+ unsigned i;
+
+ /*
+ * Forcefully reclaim buffers if the driver did not
+ * correctly return them to vb2.
+ */
+ for (i = 0; i < q->num_buffers; ++i) {
+ vb = q->bufs[i];
+ if (vb->state == VB2_BUF_STATE_ACTIVE)
+ vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
+ }
+ /* Must be zero now */
+ WARN_ON(atomic_read(&q->owned_by_drv_count));
}
- if (ret)
- dprintk(1, "qbuf: driver refused to start streaming\n");
- else
- q->retry_start_streaming = 0;
return ret;
}
* dequeued in dqbuf.
*/
list_add_tail(&vb->queued_entry, &q->queued_list);
+ q->queued_count++;
+ q->waiting_for_buffers = false;
vb->state = VB2_BUF_STATE_QUEUED;
/*
* If already streaming, give the buffer to driver for processing.
* If not, the buffer will be given to driver on next streamon.
*/
- if (q->streaming)
+ if (q->start_streaming_called)
__enqueue_in_driver(vb);
/* Fill buffer information for the userspace */
__fill_v4l2_buffer(vb, b);
- if (q->retry_start_streaming) {
+ /*
+ * If streamon has been called, and we haven't yet called
+ * start_streaming() since not enough buffers were queued, and
+ * we now have reached the minimum number of queued buffers,
+ * then we can finally call start_streaming().
+ */
+ if (q->streaming && !q->start_streaming_called &&
+ q->queued_count >= q->min_buffers_needed) {
ret = vb2_start_streaming(q);
if (ret)
return ret;
return -EINVAL;
}
- if (!q->retry_start_streaming)
- wait_event(q->done_wq, !atomic_read(&q->queued_count));
+ if (q->start_streaming_called)
+ wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
return 0;
}
EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
__fill_v4l2_buffer(vb, b);
/* Remove from videobuf queue */
list_del(&vb->queued_entry);
+ q->queued_count--;
/* go back to dequeued state */
__vb2_dqbuf(vb);
{
unsigned int i;
- if (q->retry_start_streaming) {
- q->retry_start_streaming = 0;
- q->streaming = 0;
- }
-
/*
* Tell driver to stop all transactions and release all queued
* buffers.
*/
- if (q->streaming)
+ if (q->start_streaming_called)
call_qop(q, stop_streaming, q);
q->streaming = 0;
+ q->start_streaming_called = 0;
+ q->queued_count = 0;
+
+ if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
+ for (i = 0; i < q->num_buffers; ++i)
+ if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
+ vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
+ /* Must be zero now */
+ WARN_ON(atomic_read(&q->owned_by_drv_count));
+ }
/*
* Remove all buffers from videobuf's list...
* has not already dequeued before initiating cancel.
*/
INIT_LIST_HEAD(&q->done_list);
- atomic_set(&q->queued_count, 0);
+ atomic_set(&q->owned_by_drv_count, 0);
wake_up_all(&q->done_wq);
/*
static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
- struct vb2_buffer *vb;
int ret;
if (type != q->type) {
return -EINVAL;
}
+ if (!q->num_buffers) {
+ dprintk(1, "streamon: no buffers have been allocated\n");
+ return -EINVAL;
+ }
+ if (q->num_buffers < q->min_buffers_needed) {
+ dprintk(1, "streamon: need at least %u allocated buffers\n",
+ q->min_buffers_needed);
+ return -EINVAL;
+ }
+
/*
- * If any buffers were queued before streamon,
- * we can now pass them to driver for processing.
+ * Tell driver to start streaming provided sufficient buffers
+ * are available.
*/
- list_for_each_entry(vb, &q->queued_list, queued_entry)
- __enqueue_in_driver(vb);
-
- /* Tell driver to start streaming. */
- ret = vb2_start_streaming(q);
- if (ret) {
- __vb2_queue_cancel(q);
- return ret;
+ if (q->queued_count >= q->min_buffers_needed) {
+ ret = vb2_start_streaming(q);
+ if (ret) {
+ __vb2_queue_cancel(q);
+ return ret;
+ }
}
q->streaming = 1;
* and videobuf, effectively returning control over them to userspace.
*/
__vb2_queue_cancel(q);
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
dprintk(3, "Streamoff successful\n");
return 0;
}
/*
- * There is nothing to wait for if no buffers have already been queued.
+ * There is nothing to wait for if the queue isn't streaming.
+ */
+ if (!vb2_is_streaming(q))
+ return res | POLLERR;
+ /*
+ * For compatibility with vb1: if QBUF hasn't been called yet, then
+ * return POLLERR as well. This only affects capture queues, output
+ * queues will always initialize waiting_for_buffers to false.
*/
- if (list_empty(&q->queued_list))
+ if (q->waiting_for_buffers)
return res | POLLERR;
if (list_empty(&q->done_list))
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff