[RFC 0/2] Add HDMI helpers

[Christian König]

Hi Thierry,

On 21.11.2012 16:01, Thierry Reding wrote:
> This small series is very much work in progress, but I still wanted to
> get feedback in this early stage to gather requirements from the folks
> working on the display drivers that these helpers target.
>
> Patch 1 in the series adds a generic helper to pack a structure that
> describes an HDMI AVI infoframe into the binary format as specified in
> the HDMI specification. The resulting binary buffer should be easily
> programmable into the HDMI controller.
>
> Patch 2 provides a helper to fill an HDMI AVI infoframe with data from
> a struct drm_display_mode.
>
> This is all pretty rough right now, but I think some feedback would be
> good at this point, to see if the design is at all sensible. I should
> also mention that I haven't actually tested this on real hardware yet.
> Furthermore I have plans to add something similar for the other types
> of infoframes specified by HDMI once the direction becomes clearer.
In general I like the idea of storing the informations in a C struct and 
only packing it into the binary form when needed.

I would rather like to see a complete implementation of all the 
interesting HDMI packets, including the necessary calculations/tables 
for audio timing recovery etc before it gets committed upstream.

Not sure about the separate configuration option. I'm not so much into 
the config/build system of linux (I know that it is rather complicated), 
but in general I would like to see that activated automatically as soon 
as any driver starts using it (or at least the driver depending on that 
option to be active).

Also two notes about the code in itself:
1. hdmi_avi_infoframe_pack: gets the size of the target buffer, but 
unfortunately doesn't checks it.
2. Separate the CRC calculation, we probably need that more than once.

Thanks for looking into that, keep up with the work.

Cheers,
Christian.