HDMI audio on R500

[Alex Deucher]

On 3/23/09, Russ Dill <russ.dill at gmail.com> wrote:
> On Mon, Mar 23, 2009 at 3:29 PM, Alex Deucher <alexdeucher at gmail.com> wrote:
>  > On 3/23/09, Russ Dill <russ.dill at gmail.com> wrote:
>  >> I have a laptop with an HDMI output. In Vista, I can get the Realtek
>  >>  HD audio driver to pass audio through the HDMI interface. In Linux, no
>  >>  amount of fiddling with IEC958 switiches and PCM devices will get
>  >>  audio to come through the HDMI interface.
>  >>
>  >>  00:00.0 Host bridge: ATI Technologies Inc RS480 Host Bridge (rev 10)
>  >>  [...]
>  >>  00:14.2 Audio device: ATI Technologies Inc IXP SB4x0 High Definition
>  >>  Audio Controller (rev 01)
>  >>  [...]
>  >>  01:00.0 VGA compatible controller: ATI Technologies Inc M56P [Radeon
>  >>  Mobility X1600]
>  >>
>  >>  An alsa developer was thinking that since the video chip interfaces
>  >>  with the TMDS encoder chip and must somehow be involved. Is anyone
>  >>  aware of any registers or bits that would enable HDMI audio
>  >>  pass-through?
>  >
>  > Native HDMI audio support is only available on RS6xx/R6xx/R7xx chips.
>  > I suspect there is either some platform specific magic required in to
>  > get it to work (i.e., some external component does the audio/video
>  > mixing), or your laptop's oem used an external hdmi encoder.  Can you
>  > send me your video bios?
>  >
>  > as root:
>  > cd /sys/bus/pci/devices/<pci bus id>
>  > echo 1 > rom
>  > cat rom > /tmp/vbios.rom
>  > echo 0 > rom
>
>
> Attached
>
>

Looks pretty standard; internal tmds used for hdmi port.  I suspect
hdmi audio is implemented via some oem-specific solution.

Alex