[Intel-gfx] i915: How to set the AVI InfoFrame on a HDMI output?

David Härdeman david at hardeman.nu
Tue Jul 27 15:58:44 CEST 2010

On Tue, July 27, 2010 03:41, Zhenyu Wang wrote:
> On 2010.07.26 20:36:49 +0200, David Härdeman wrote:
>> Hi,
>> I'm trying to play with some different AVI InfoFrame settings for the
>> HDMI output on my DG45FC (G45 Intel graphics hardware, HDMI connector on
>> the motherboard) but I can't seem to find any references to it in the
>> i915 driver or in the programming specs.
>> drivers/gpu/drm/i915/intel_sdvo.c has code for setting an avi infoframe
>> for hdmi outputs, but it doesn't seem to be used on my board (I tried
>> sprinkling some printk's in there). I guess it's only for ADD2 type
>> addon boards?
>> So far I'm guessing that drivers/gpu/drm/i915/intel_hdmi.c is
>> responsible but there is no code in there that deals with the avi
>> infoframe and I haven't been able to find anything in the programming
>> manuals from the intel linux graphics website.
>> Could anyone point me in the right direction?
>> And on a related note, does anyone know if the hardware supports HDMI
>> CEC and where I might find the relevant hardware documentation?
> We don't have AVI infoframe support for native HDMI port now.
> Looks our public doc missed register info for VIDEO_DIP_CTL/DATA,
> that I assume should be used for that. If you have requirement to
> support that maybe for some special sink device, I can try to ask
> if that info should be updated in the spec.

Thanks for the VIDEO_DIP_CTL/DATA pointer, I found the relevant passages
in the docs now (not sure why I didn't find it myself), it's in sections
2.8.8 and 2.8.9 of "Volume 3: Display Registers, Revision 1.0c".

The intel_audio_dump tool also seems to dump at least the VIDEO_DIP_CTL
part :)

David Härdeman

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