[libcamera-devel] [PATCH 1/3] libcamera: v4l2_videodevice: Remove setting of buffer sequence

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2022-03-23 00:12:09)
> Hi Umang,
> 
> Thank you for the patch.
> 
> On Thu, Mar 17, 2022 at 04:17:38PM +0530, Umang Jain via libcamera-devel wrote:
> > The struct v4l2_buffer documentation [1] clearly states
> > that setting of the sequence is done by the driver. libcamera does
> > not really need to set this field while queuing the buffer(s).
> > 
> > [1]: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/buffer.html#struct-v4l2-buffer
> > 
> > Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

I always thought sequence numbers should be propogated like the
timestamp, but if the kernel doesn't do it - then no point setting it
indeed.


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> 
> > ---
> >  src/libcamera/v4l2_videodevice.cpp | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
> > index 5f36ee20..5580269f 100644
> > --- a/src/libcamera/v4l2_videodevice.cpp
> > +++ b/src/libcamera/v4l2_videodevice.cpp
> > @@ -1600,7 +1600,6 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer)
> >                       buf.length = planes[0].length;
> >               }
> >  
> > -             buf.sequence = metadata.sequence;
> >               buf.timestamp.tv_sec = metadata.timestamp / 1000000000;
> >               buf.timestamp.tv_usec = (metadata.timestamp / 1000) % 1000000;
> >       }
> 
> -- 
> Regards,
> 
> Laurent Pinchart