Re: [PATCH v2 1/5] video: move mediabus format definition to a more standard place

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Mon, 29 Sep 2014 23:41:09 +0300
Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:

> Hi Boris,
> 
> Thank you for the patch.
> 
> On Monday 29 September 2014 16:02:39 Boris Brezillon wrote:
> > Rename mediabus formats and move the enum into a separate header file so
> > that it can be used by DRM/KMS subsystem without any reference to the V4L2
> > subsystem.
> > 
> > Old V4L2_MBUS_FMT_ definitions are now macros that points to VIDEO_BUS_FMT_
> > definitions.
> > 
> > Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
> > Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> > ---
> >  include/uapi/linux/Kbuild             |   1 +
> >  include/uapi/linux/v4l2-mediabus.h    | 183 +++++++++++++------------------
> >  include/uapi/linux/video-bus-format.h | 127 +++++++++++++++++++++++
> >  3 files changed, 207 insertions(+), 104 deletions(-)
> >  create mode 100644 include/uapi/linux/video-bus-format.h
> 
> One of the self-inflicted rules in V4L2 is to properly document every new 
> media bus format when adding it to the kernel. The documentation is located in 
> Documentation/DocBook/media/v4l/subdev-formats.xml. If we move the formats to 
> a centralized header (which I believe is a good idea), we should also update 
> the documentation, and possibly its location. I really want to avoid getting 
> undocumented formats merged, and this will happen if we don't make the rule 
> clear and/or don't make the documentation easily accessible.

Any idea where this new documentation should go
(Documentation/DocBook/video/video-bus-formats.xml) ?

> 
> Incidentally, patch 2/5 in this series is missing a documentation update ;-)

Yep, regarding this patch, I wonder if it's really necessary to add
new formats to the v4l2_mbus_pixelcode enum.
If we want to move to this new common definition (across the video
related subsytems), we should deprecate the old enum
v4l2_mbus_pixelcode, and this start by not adding new formats, don't
you think ?

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com