Hi Gustavo,
On Fri, Oct 20, 2017 at 07:50:11PM -0200, Gustavo Padovan wrote:
From: Gustavo Padovan <gustavo.pado...@collabora.com>
If V4L2_BUF_FLAG_OUT_FENCE flag is present on the QBUF call we create
an out_fence and send to userspace on the V4L2_EVENT_OUT_FENCE when
the buffer is queued to the driver, or right away if the queue is ordered
both in VB2 and in the driver.
The fence is signaled on buffer_done(), when the job on the buffer is
finished.
v5:
- delay fd_install to DQ_EVENT (Hans)
- if queue is fully ordered send OUT_FENCE event right away
(Brian)
- rename 'q->ordered' to 'q->ordered_in_driver'
- merge change to implement OUT_FENCE event here
v4:
- return the out_fence_fd in the BUF_QUEUED event(Hans)
v3: - add WARN_ON_ONCE(q->ordered) on requeueing (Hans)
- set the OUT_FENCE flag if there is a fence pending (Hans)
- call fd_install() after vb2_core_qbuf() (Hans)
- clean up fence if vb2_core_qbuf() fails (Hans)
- add list to store sync_file and fence for the next queued buffer
v2: check if the queue is ordered.
Signed-off-by: Gustavo Padovan <gustavo.pado...@collabora.com>
---
drivers/media/v4l2-core/v4l2-event.c | 2 ++
drivers/media/v4l2-core/videobuf2-core.c | 25 +++++++++++++++
drivers/media/v4l2-core/videobuf2-v4l2.c | 55 ++++++++++++++++++++++++++++++++
3 files changed, 82 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-event.c
b/drivers/media/v4l2-core/v4l2-event.c
index 6274e3e174e0..275da224ace4 100644
--- a/drivers/media/v4l2-core/v4l2-event.c
+++ b/drivers/media/v4l2-core/v4l2-event.c
@@ -385,6 +385,8 @@ int v4l2_subscribe_event_v4l2(struct v4l2_fh *fh,
switch (sub->type) {
case V4L2_EVENT_CTRL:
return v4l2_ctrl_subscribe_event(fh, sub);
+ case V4L2_EVENT_OUT_FENCE:
+ return v4l2_event_subscribe(fh, sub, VIDEO_MAX_FRAME, NULL);
}
return -EINVAL;
}
diff --git a/drivers/media/v4l2-core/videobuf2-core.c
b/drivers/media/v4l2-core/videobuf2-core.c
index c7ba67bda5ac..21e2052776c1 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -354,6 +354,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum
vb2_memory memory,
vb->planes[plane].length = plane_sizes[plane];
vb->planes[plane].min_length = plane_sizes[plane];
}
+ vb->out_fence_fd = -1;
q->bufs[vb->index] = vb;
/* Allocate video buffer memory for the MMAP type */
@@ -934,10 +935,24 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum
vb2_buffer_state state)
case VB2_BUF_STATE_QUEUED:
return;
case VB2_BUF_STATE_REQUEUEING:
+ /*
+ * Explicit synchronization requires ordered queues for now,
+ * so WARN_ON if we are requeuing on an ordered queue.
+ */
+ if (vb->out_fence)
+ WARN_ON_ONCE(q->ordered_in_driver);
+
if (q->start_streaming_called)
__enqueue_in_driver(vb);
return;
default:
+ if (state == VB2_BUF_STATE_ERROR)
+ dma_fence_set_error(vb->out_fence, -ENOENT);
+ dma_fence_signal(vb->out_fence);
+ dma_fence_put(vb->out_fence);
+ vb->out_fence = NULL;
+ vb->out_fence_fd = -1;
+
/* Inform any processes that may be waiting for buffers */
wake_up(&q->done_wq);
break;
@@ -1235,6 +1250,9 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
trace_vb2_buf_queue(q, vb);
call_void_vb_qop(vb, buf_queue, vb);
+
+ if (!(q->is_output || q->ordered_in_vb2))
+ call_void_bufop(q, send_out_fence, vb);
}
static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
@@ -1451,6 +1469,7 @@ static struct dma_fence *__set_in_fence(struct vb2_queue
*q,
}
q->last_fence = dma_fence_get(fence);
+ call_void_bufop(q, send_out_fence, vb);
}
return fence;
@@ -1840,6 +1859,11 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
}
/*
+ * Renew out-fence context.
+ */
Why is that? I don't think I understand the nuances of fence contexts.
+ q->out_fence_context = dma_fence_context_alloc(1);
+
+ /*
* Remove all buffers from videobuf's list...
*/
INIT_LIST_HEAD(&q->queued_list);
@@ -2171,6 +2195,7 @@ int vb2_core_queue_init(struct vb2_queue *q)
spin_lock_init(&q->done_lock);
mutex_init(&q->mmap_lock);
init_waitqueue_head(&q->done_wq);
+ q->out_fence_context = dma_fence_context_alloc(1);
if (q->buf_struct_size == 0)
q->buf_struct_size = sizeof(struct vb2_buffer);
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c
b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 4c09ea007d90..9fb01ddefdc9 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -32,6 +32,11 @@
#include <media/videobuf2-v4l2.h>
+struct out_fence_data {
+ int fence_fd;
+ struct file *file;
+};
+
static int debug;
module_param(debug, int, 0644);
@@ -138,6 +143,38 @@ static void __copy_timestamp(struct vb2_buffer *vb, const
void *pb)
}
};
+static void __fd_install_at_dequeue_cb(void *data)
+{
+ struct out_fence_data *of = data;
+
+ fd_install(of->fence_fd, of->file);
+ kfree(of);
Is it possible for the user to never dequeue the event? In that case
the fd and sync_file would leak I guess.
+}
+
+static void __send_out_fence(struct vb2_buffer *vb)
+{
+ struct video_device *vdev = to_video_device(vb->vb2_queue->dev);
+ struct v4l2_fh *fh = vdev->queue->owner;
+ struct v4l2_event event;
+ struct out_fence_data *of;
+
+ if (vb->out_fence_fd < 0)
+ return;
+
+ memset(&event, 0, sizeof(event));
+ event.type = V4L2_EVENT_OUT_FENCE;
+ event.u.out_fence.index = vb->index;
+ event.u.out_fence.out_fence_fd = vb->out_fence_fd;
+
+ of = kmalloc(sizeof(*of), GFP_KERNEL);
+ of->fence_fd = vb->out_fence_fd;
+ of->file = vb->sync_file->file;
+
+ v4l2_event_queue_fh_with_cb(fh, &event, __fd_install_at_dequeue_cb, of);
+
+ vb->sync_file = NULL;
See the comment above about never dequeuing the event - maybe you need
to keep hold of the sync file to be able to clean it up in-case the
user never dequeues. If not, then you could set vb->out_fence_fd = -1
here too.
I've been looking at your v4l2-fences branch on kernel.org, which
looks quite different. Is this the newer version?
Cheers,
-Brian
+}
+
static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
{
static bool check_once;
@@ -185,6 +222,12 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q,
struct v4l2_buffer *b,
return -EINVAL;
}
+ if (!q->ordered_in_driver && (b->flags & V4L2_BUF_FLAG_OUT_FENCE)) {
+ dprintk(1, "%s: out-fence doesn't work on unordered queues\n",
+ opname);
+ return -EINVAL;
+ }
+
return __verify_planes_array(q->bufs[b->index], b);
}
@@ -213,6 +256,8 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void
*pb)
b->reserved = 0;
b->fence_fd = -1;
+ if (vb->out_fence)
+ b->flags |= V4L2_BUF_FLAG_OUT_FENCE;
if (vb->in_fence)
b->flags |= V4L2_BUF_FLAG_IN_FENCE;
else
@@ -456,6 +501,7 @@ static const struct vb2_buf_ops v4l2_buf_ops = {
.fill_user_buffer = __fill_v4l2_buffer,
.fill_vb2_buffer = __fill_vb2_buffer,
.copy_timestamp = __copy_timestamp,
+ .send_out_fence = __send_out_fence,
};
/**
@@ -593,6 +639,15 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
}
}
+ if (b->flags & V4L2_BUF_FLAG_OUT_FENCE) {
+ ret = vb2_setup_out_fence(q, b->index);
+ if (ret) {
+ dprintk(1, "failed to set up out-fence\n");
+ dma_fence_put(fence);
+ return ret;
+ }
+ }
+
return vb2_core_qbuf(q, b->index, b, fence);
}
EXPORT_SYMBOL_GPL(vb2_qbuf);
--
2.13.6
