From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx> Turn the reserved2 field into fence_fd that we will use to send an in-fence to the kernel and return an out-fence from the kernel to userspace. Two new flags were added, V4L2_BUF_FLAG_IN_FENCE, that should be used when sending a fence to the kernel to be waited on, and V4L2_BUF_FLAG_OUT_FENCE, to ask the kernel to give back an out-fence. v2: add documentation Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx> --- Documentation/media/uapi/v4l/buffer.rst | 19 +++++++++++++++++++ drivers/media/usb/cpia2/cpia2_v4l.c | 2 +- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 4 ++-- drivers/media/v4l2-core/videobuf2-v4l2.c | 2 +- include/uapi/linux/videodev2.h | 4 +++- 5 files changed, 26 insertions(+), 5 deletions(-) diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst index ae6ee73f151c..664507ad06c6 100644 --- a/Documentation/media/uapi/v4l/buffer.rst +++ b/Documentation/media/uapi/v4l/buffer.rst @@ -648,6 +648,25 @@ Buffer Flags - Start Of Exposure. The buffer timestamp has been taken when the exposure of the frame has begun. This is only valid for the ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` buffer type. + * .. _`V4L2-BUF-FLAG-IN-FENCE`: + + - ``V4L2_BUF_FLAG_IN_FENCE`` + - 0x00200000 + - Ask V4L2 to wait on fence passed in ``fence_fd`` field. The buffer + won't be queued to the driver until the fence signals. + + * .. _`V4L2-BUF-FLAG-OUT-FENCE`: + + - ``V4L2_BUF_FLAG_OUT_FENCE`` + - 0x00400000 + - Request a fence for the next buffer to be queued to V4L2 driver. + The fence received back through the ``fence_fd`` field doesn't + necessarily relate to the current buffer in the + :ref:`VIDIOC_QBUF <VIDIOC_QBUF>` ioctl. Although, most of the time + the fence will relate to the current buffer it can't be guaranteed. + So to tell userspace which buffer is associated to the out_fence, + one should listen for the ``V4L2_EVENT_BUF_QUEUED`` event that + provide the id of the buffer when it is queued to the V4L2 driver. diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c index 3dedd83f0b19..6cde686bf44c 100644 --- a/drivers/media/usb/cpia2/cpia2_v4l.c +++ b/drivers/media/usb/cpia2/cpia2_v4l.c @@ -948,7 +948,7 @@ static int cpia2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->sequence = cam->buffers[buf->index].seq; buf->m.offset = cam->buffers[buf->index].data - cam->frame_buffer; buf->length = cam->frame_size; - buf->reserved2 = 0; + buf->fence_fd = -1; buf->reserved = 0; memset(&buf->timecode, 0, sizeof(buf->timecode)); diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 821f2aa299ae..d624fb5df130 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -370,7 +370,7 @@ struct v4l2_buffer32 { __s32 fd; } m; __u32 length; - __u32 reserved2; + __s32 fence_fd; __u32 reserved; }; @@ -533,8 +533,8 @@ static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user put_user(kp->timestamp.tv_usec, &up->timestamp.tv_usec) || copy_to_user(&up->timecode, &kp->timecode, sizeof(struct v4l2_timecode)) || put_user(kp->sequence, &up->sequence) || - put_user(kp->reserved2, &up->reserved2) || put_user(kp->reserved, &up->reserved) || + put_user(kp->fence_fd, &up->fence_fd) || put_user(kp->length, &up->length)) return -EFAULT; diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c index 0c0669976bdc..110fb45fef6f 100644 --- a/drivers/media/v4l2-core/videobuf2-v4l2.c +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c @@ -203,7 +203,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb) b->timestamp = ns_to_timeval(vb->timestamp); b->timecode = vbuf->timecode; b->sequence = vbuf->sequence; - b->reserved2 = 0; + b->fence_fd = -1; b->reserved = 0; if (q->is_multiplanar) { diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 185d6a0acc06..e5abab9a908c 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -924,7 +924,7 @@ struct v4l2_buffer { __s32 fd; } m; __u32 length; - __u32 reserved2; + __s32 fence_fd; __u32 reserved; }; @@ -961,6 +961,8 @@ struct v4l2_buffer { #define V4L2_BUF_FLAG_TSTAMP_SRC_SOE 0x00010000 /* mem2mem encoder/decoder */ #define V4L2_BUF_FLAG_LAST 0x00100000 +#define V4L2_BUF_FLAG_IN_FENCE 0x00200000 +#define V4L2_BUF_FLAG_OUT_FENCE 0x00400000 /** * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor -- 2.13.5