lkml.org 
[lkml]   [2017]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC v5 09/11] [media] vb2: add infrastructure to support out-fences
Date
On Thursday, November 16, 2017 2:10:55 AM JST, Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan@collabora.com>
>
> Add vb2_setup_out_fence() and the needed members to struct vb2_buffer.
>
> v3:
> - Do not hold yet another ref to the out_fence (Brian Starkey)
>
> v2: - change it to reflect fd_install at DQEVENT
> - add fence context for out-fences
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
> ---
> drivers/media/v4l2-core/videobuf2-core.c | 28 ++++++++++++++++++++++++++++
> include/media/videobuf2-core.h | 20 ++++++++++++++++++++
> 2 files changed, 48 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c
> b/drivers/media/v4l2-core/videobuf2-core.c
> index 26de4c80717d..8b4f0e9bcb36 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -24,8 +24,10 @@
> #include <linux/freezer.h>
> #include <linux/kthread.h>
> #include <linux/dma-fence-array.h>
> +#include <linux/sync_file.h>
>
> #include <media/videobuf2-core.h>
> +#include <media/videobuf2-fence.h>
> #include <media/v4l2-mc.h>
>
> #include <trace/events/vb2.h>
> @@ -1320,6 +1322,32 @@ int vb2_core_prepare_buf(struct
> vb2_queue *q, unsigned int index, void *pb)
> }
> EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
>
> +int vb2_setup_out_fence(struct vb2_queue *q, unsigned int index)
> +{
> + struct vb2_buffer *vb;
> +
> + vb = q->bufs[index];
> +
> + vb->out_fence_fd = get_unused_fd_flags(O_CLOEXEC);

out_fence_fd is allocated in this patch but not used anywhere for the
moment.
For consistency, maybe move its allocation to the next patch, or move the
call
to fd_install() here if that is possible? In both cases, the call to
get_unused_fd() can be moved right before fd_install() so you don't need to
call put_unused_fd() in the error paths below.

... same thing for sync_file too. Maybe this patch can just be merged into
the next one? The current patch just creates an incomplete version of
vb2_setup_out_fence() for which no user exist yet.

> +
> + vb->out_fence = vb2_fence_alloc(q->out_fence_context);
> + if (!vb->out_fence) {
> + put_unused_fd(vb->out_fence_fd);
> + return -ENOMEM;
> + }
> +
> + vb->sync_file = sync_file_create(vb->out_fence);
> + if (!vb->sync_file) {
> + put_unused_fd(vb->out_fence_fd);
> + dma_fence_put(vb->out_fence);
> + vb->out_fence = NULL;
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(vb2_setup_out_fence);
> +
> /**
> * vb2_start_streaming() - Attempt to start streaming.
> * @q: videobuf2 queue
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 5f48c7be7770..a9b0697bd782 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -259,6 +259,10 @@ struct vb2_buffer {
> * using the buffer (queueing to the driver)
> * fence_cb: fence callback information
> * fence_cb_lock: protect callback signal/remove
> + * out_fence_fd: the out_fence_fd to be shared with userspace.
> + * out_fence: the out-fence associated with the buffer once
> + * it is queued to the driver.
> + * sync_file: the sync file to wrap the out fence
> */
> enum vb2_buffer_state state;
>
> @@ -269,6 +273,10 @@ struct vb2_buffer {
> struct dma_fence_cb fence_cb;
> spinlock_t fence_cb_lock;
>
> + int out_fence_fd;
> + struct dma_fence *out_fence;
> + struct sync_file *sync_file;
> +
> #ifdef CONFIG_VIDEO_ADV_DEBUG
> /*
> * Counters for how often these buffer-related ops are
> @@ -514,6 +522,7 @@ struct vb2_buf_ops {
> * @last_buffer_dequeued: used in poll() and DQBUF to
> immediately return if the
> * last decoded buffer was already dequeued. Set for capture queues
> * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
> + * @out_fence_context: the fence context for the out fences
> * @last_fence: last in-fence received. Used to keep ordering.
> * @fileio: file io emulator internal data, used only if emulator is active
> * @threadio: thread io internal data, used only if thread is active
> @@ -569,6 +578,7 @@ struct vb2_queue {
> unsigned int copy_timestamp:1;
> unsigned int last_buffer_dequeued:1;
>
> + u64 out_fence_context;
> struct dma_fence *last_fence;
>
> struct vb2_fileio_data *fileio;
> @@ -740,6 +750,16 @@ int vb2_core_create_bufs(struct vb2_queue
> *q, enum vb2_memory memory,
> int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int
> index, void *pb);
>
> /**
> + * vb2_setup_out_fence() - setup new out-fence
> + * @q: The vb2_queue where to setup it
> + * @index: index of the buffer
> + *
> + * Setup the file descriptor, the fence and the sync_file for the next
> + * buffer to be queued and add everything to the tail of the
> q->out_fence_list.
> + */
> +int vb2_setup_out_fence(struct vb2_queue *q, unsigned int index);
> +
> +/**
> * vb2_core_qbuf() - Queue a buffer from userspace
> *
> * @q: videobuf2 queue

\
 
 \ /
  Last update: 2017-11-17 17:18    [W:0.353 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site