[RFC 01/10] [media] vb2: add explicit fence user API

Gustavo Padovan
2017-03-13T19:20:47Z

From: Gustavo Padovan <gustavo.padovan@collabora.com>

Turn the reserved2 field into fence_fd that we will use to send
an in-fence to the kernel return an out-fence from the kernel to
userspace.

Two new flags were added, V4L2_BUF_FLAG_IN_FENCE and
V4L2_BUF_FLAG_OUT_FENCE. They should be used when setting in-fence and
out-fence, respectively.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
---
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 4 ++--
drivers/media/v4l2-core/videobuf2-v4l2.c | 2 +-
include/uapi/linux/videodev2.h | 6 ++++--
3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index eac9565..0a522cb 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -348,7 +348,7 @@ struct v4l2_buffer32 {
__s32 fd;
} m;
__u32 length;
- __u32 reserved2;
+ __s32 fence_fd;
__u32 reserved;
};

@@ -511,7 +511,7 @@ 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->fence_fd, &up->fence_fd) ||
put_user(kp->reserved, &up->reserved) ||
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 3529849..d23c1bf 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 45184a2..3b6cfa6 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -911,7 +911,7 @@ struct v4l2_buffer {
__s32 fd;
} m;
__u32 length;
- __u32 reserved2;
+ __s32 fence_fd;
__u32 reserved;
};

@@ -946,8 +946,10 @@ struct v4l2_buffer {
#define V4L2_BUF_FLAG_TSTAMP_SRC_MASK 0x00070000
#define V4L2_BUF_FLAG_TSTAMP_SRC_EOF 0x00000000
#define V4L2_BUF_FLAG_TSTAMP_SRC_SOE 0x00010000
+#define V4L2_BUF_FLAG_IN_FENCE 0x00100000
+#define V4L2_BUF_FLAG_OUT_FENCE 0x00200000
/* mem2mem encoder/decoder */
-#define V4L2_BUF_FLAG_LAST 0x00100000
+#define V4L2_BUF_FLAG_LAST 0x00400000

/**
* struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
--
2.9.3