Re: [RFC PATCH 4/9] videodev2.h: Add request field to v4l2_buffer

[Alexandre Courbot]

On Fri, Jan 12, 2018 at 7:22 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> 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.

Indeed, fixed.

>
> 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.

All done, thanks!