Hi Hans,
On Friday 18 December 2015 12:20:54 Hans Verkuil wrote:
> On 12/17/2015 09:40 AM, Laurent Pinchart wrote:
> > Let userspace specify a request ID when getting or setting formats or
> > selection rectangles.
> >
> > From a userspace point of view the API change is minimized and doesn't
> > require any new ioctl.
> >
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > ---
> >
> > include/uapi/linux/v4l2-subdev.h | 15 +++++++++++++--
> > 1 file changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/uapi/linux/v4l2-subdev.h
> > b/include/uapi/linux/v4l2-subdev.h index dbce2b554e02..2f1691ce9df5
> > 100644
> > --- a/include/uapi/linux/v4l2-subdev.h
> > +++ b/include/uapi/linux/v4l2-subdev.h
> > @@ -32,10 +32,12 @@
> > * enum v4l2_subdev_format_whence - Media bus format type
> > * @V4L2_SUBDEV_FORMAT_TRY: try format, for negotiation only
> > * @V4L2_SUBDEV_FORMAT_ACTIVE: active format, applied to the device
> > + * @V4L2_SUBDEV_FORMAT_REQUEST: format stored in request
> > */
> > enum v4l2_subdev_format_whence {
> > V4L2_SUBDEV_FORMAT_TRY = 0,
> > V4L2_SUBDEV_FORMAT_ACTIVE = 1,
> > + V4L2_SUBDEV_FORMAT_REQUEST = 2,
> > };
> >
> > /**
> > @@ -43,12 +45,17 @@ enum v4l2_subdev_format_whence {
> > * @which: format type (from enum v4l2_subdev_format_whence)
> > * @pad: pad number, as reported by the media API
> > * @format: media bus format (format code and frame size)
> > + * @request: request ID (when which is set to V4L2_SUBDEV_FORMAT_REQUEST)
> > + * @reserved2: for future use, set to zero for now
> > + * @reserved: for future use, set to zero for now
> > */
> > struct v4l2_subdev_format {
> > __u32 which;
> > __u32 pad;
> > struct v4l2_mbus_framefmt format;
> > - __u32 reserved[8];
> > + __u16 request;
> > + __u16 reserved2;
> > + __u32 reserved[7];
>
> I would prefer:
>
> __u16 request;
> __u16 reserved[15];
>
> > };
> >
> > /**
> > @@ -139,6 +146,8 @@ struct v4l2_subdev_frame_interval_enum {
> > * defined in v4l2-common.h; V4L2_SEL_TGT_* .
> > * @flags: constraint flags, defined in v4l2-common.h; V4L2_SEL_FLAG_*.
> > * @r: coordinates of the selection window
> > + * @request: request ID (when which is set to V4L2_SUBDEV_FORMAT_REQUEST)
> > + * @reserved2: for future use, set to zero for now
> > * @reserved: for future use, set to zero for now
> > *
> > * Hardware may use multiple helper windows to process a video stream.
> > @@ -151,7 +160,9 @@ struct v4l2_subdev_selection {
> > __u32 target;
> > __u32 flags;
> > struct v4l2_rect r;
> > - __u32 reserved[8];
> > + __u16 request;
> > + __u16 reserved2;
> > + __u32 reserved[7];
>
> Ditto.
>
> Generally apps do a memset of reserved, and that will just keep working.
> But adding a reserved2 field means that they have to explicitly set
> reserved2 to 0, which won't happen.
Agreed. Consider it fixed.
> > };
> >
> > /* Backwards compatibility define --- to be removed */
--
Regards,
Laurent Pinchart
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