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    SubjectRe: [PATCH] [media] hdmi: added functions for MPEG InfoFrames
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    Hello Thierry,

    2015-11-19 13:29 GMT+01:00 Enric Balletbo Serra <eballetbo@gmail.com>:
    > Hello Thierry,
    >
    > 2015-11-19 12:51 GMT+01:00 Thierry Reding <treding@nvidia.com>:
    >> On Tue, Nov 17, 2015 at 11:55:53PM +0100, Enric Balletbo Serra wrote:
    >>> Hello Thierry,
    >>>
    >>> 2015-11-17 13:55 GMT+01:00 Thierry Reding <treding@nvidia.com>:
    >>> > On Mon, Nov 16, 2015 at 05:28:24PM +0100, Enric Balletbo Serra wrote:
    >>> >> Hello Thierry,
    >>> >>
    >>> >> Many thanks for your comments.
    >>> >>
    >>> >> 2015-11-16 12:50 GMT+01:00 Thierry Reding <treding@nvidia.com>:
    >>> >> > On Sat, Nov 14, 2015 at 07:38:19PM +0100, Enric Balletbo i Serra wrote:
    >>> >> >> The MPEG Source (MS) InfoFrame is in EIA/CEA-861B. It describes aspects of
    >>> >> >> the compressed video stream that were used to produce the uncompressed
    >>> >> >> video.
    >>> >> >>
    >>> >> >> The patch adds functions to work with MPEG InfoFrames.
    >>> >> >>
    >>> >> >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
    >>> >> >> ---
    >>> >> >> drivers/video/hdmi.c | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++
    >>> >> >> include/linux/hdmi.h | 24 ++++++++
    >>> >> >> 2 files changed, 180 insertions(+)
    >>> >> >
    >>> >> > According to the CEA specification a source is expected to send this
    >>> >> > type of infoframe once per video frame. I'm curious how you envision
    >>> >> > this to be ensured. Would hardware provide a mechanism to store this
    >>> >> > data and send the infoframe automatically? How would you ensure that
    >>> >> > updates sent to the hardware match the upcoming frame?
    >>> >> >
    >>> >>
    >>> >> To be honest I'm not sure if I have the full picture. In the use case
    >>> >> I'm trying there is a hardware mechanism to store the data and send
    >>> >> the infoframe through a "Packet Send Control Register".
    >>> >
    >>> > Okay, sounds like the hardware will automatically send out packets at
    >>> > the right time. That still leaves open the issue of how to ensure this
    >>> > is synchronized with userspace. Perhaps this could be done by attaching
    >>> > a property to a framebuffer, so that we'd know what exact frame the meta
    >>> > data is attached to and when to update the FIFOs for the infoframe.
    >>> >
    >>> > Usually it's a good idea to send this type of patch as part of a larger
    >>> > series precisely so that people can see how it is used. That should make
    >>> > it easier to see if this is good enough or needs some more thought on
    >>> > how to synchronize. Do you have any code that you could post that makes
    >>> > use of this new infoframe?
    >>> >
    >>>
    >>> I was thinking use this and other helpers in the anx7814 bridge
    >>> driver[1], I thought that this patch should go through another tree,
    >>> this is the reason why I send it separately, but If you want or you
    >>> prefer I can send as part of these patch series.
    >>>
    >>> [1] https://lkml.org/lkml/2015/11/13/284
    >>
    >> I haven't seen those patches yet. I should've been Cc'ed on those
    >> patches since I'm technically the maintainer of drm/bridge. Did the
    >> get_maintainer.pl script not list me?
    >>
    >
    > Mmm, just checked and yes, get_maintainer list you, so probably I did
    > something getting the maintainers.
    > Sorry.
    >
    >> In my opinion, it's usually a good idea to keep all dependencies in a
    >> single series, just so people get a better picture of what you're
    >> submitting. Of course that's just my opinion, somebody else may yell at
    >> you because they get Cc'ed on patches that they're not interested in...
    >>
    >> As for merging patches, it's usually best to let maintainers figure that
    >> out once the series is in good shape.
    >>
    >> Thierry


    As you suggested I included this patch series with anx7814 bridge
    driver series. So you can see the context. Please feel free to comment
    anything.

    https://lkml.org/lkml/2015/12/4/66

    Regards,

    Enric


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