Re: [RFC PATCH 4/9] videodev2.h: Add request field to v4l2_buffer
From: Hans Verkuil
Date: Fri Jan 12 2018 - 05:22:34 EST
On 12/15/17 08:56, Alexandre Courbot wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> When queuing buffers allow for passing the request ID that
> should be associated with this buffer.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> [acourbot@xxxxxxxxxxxx: make request ID 32-bit]
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
> ---
> drivers/media/usb/cpia2/cpia2_v4l.c | 2 +-
> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 7 ++++---
> drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++--
> drivers/media/v4l2-core/videobuf2-v4l2.c | 3 ++-
> include/media/videobuf2-v4l2.h | 2 ++
> include/uapi/linux/videodev2.h | 3 ++-
> 6 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c
> index 3dedd83f0b19..7217dde95a8a 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->request = 0;
> 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..94f07c3b0b53 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;
> + __u32 request;
> __u32 reserved;
> };
>
> @@ -438,7 +438,8 @@ static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user
> get_user(kp->type, &up->type) ||
> get_user(kp->flags, &up->flags) ||
> get_user(kp->memory, &up->memory) ||
> - get_user(kp->length, &up->length))
> + get_user(kp->length, &up->length) ||
> + get_user(kp->request, &up->request))
> return -EFAULT;
>
> if (V4L2_TYPE_IS_OUTPUT(kp->type))
> @@ -533,7 +534,7 @@ 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->request, &up->request) ||
> put_user(kp->reserved, &up->reserved) ||
> put_user(kp->length, &up->length))
> return -EFAULT;
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index ec4ecd5aa8bf..8d041247e97f 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -437,13 +437,13 @@ static void v4l_print_buffer(const void *arg, bool write_only)
> const struct v4l2_plane *plane;
> int i;
>
> - pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, flags=0x%08x, field=%s, sequence=%d, memory=%s",
> + pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, request=%u, flags=0x%08x, field=%s, sequence=%d, memory=%s",
> p->timestamp.tv_sec / 3600,
> (int)(p->timestamp.tv_sec / 60) % 60,
> (int)(p->timestamp.tv_sec % 60),
> (long)p->timestamp.tv_usec,
> p->index,
> - prt_names(p->type, v4l2_type_names),
> + prt_names(p->type, v4l2_type_names), p->request,
> p->flags, prt_names(p->field, v4l2_field_names),
> p->sequence, prt_names(p->memory, v4l2_memory_names));
>
> diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
> index 0c0669976bdc..bde7b8a3a303 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->request = vbuf->request;
> b->reserved = 0;
>
> if (q->is_multiplanar) {
> @@ -320,6 +320,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb,
> }
> vb->timestamp = 0;
> vbuf->sequence = 0;
> + vbuf->request = b->request;
>
> if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
> if (b->memory == VB2_MEMORY_USERPTR) {
> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
> index 036127c54bbf..ef2be0ccff14 100644
> --- a/include/media/videobuf2-v4l2.h
> +++ b/include/media/videobuf2-v4l2.h
> @@ -31,6 +31,7 @@
> * @field: enum v4l2_field; field order of the image in the buffer
> * @timecode: frame timecode
> * @sequence: sequence count of this frame
> + * @request: request used by the buffer
> *
> * Should contain enough information to be able to cover all the fields
> * of struct v4l2_buffer at videodev2.h
> @@ -42,6 +43,7 @@ struct vb2_v4l2_buffer {
> __u32 field;
> struct v4l2_timecode timecode;
> __u32 sequence;
> + __u32 request;
> };
>
> /*
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 1c095b5a99c5..0650e8d14971 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -902,6 +902,7 @@ struct v4l2_plane {
> * @length: size in bytes of the buffer (NOT its payload) for single-plane
> * buffers (when type != *_MPLANE); number of elements in the
> * planes array for multi-plane buffers
> + * @request: this buffer should use this request
> *
> * Contains data exchanged by application and driver using one of the Streaming
> * I/O methods.
> @@ -925,7 +926,7 @@ struct v4l2_buffer {
> __s32 fd;
> } m;
> __u32 length;
> - __u32 reserved2;
> + __u32 request;
Aren't file descriptors signed integers? So this would become __s32.
I also think I would prefer to rename this to request_fd, so it is clear this is a
file descriptor. Same for struct vb2_v4l2_buffer and struct v4l2_buffer32.
Also update the @request descriptions in the comments and v4l_print_buffer.
Regards,
Hans
> __u32 reserved;
> };
>
>