[alsa-devel] [RFC PATCH 0/5] DisplayPort Audio on Cherrytrail

[Takashi Iwai]

On Thu, 26 Jan 2017 21:05:36 +0100,
Pierre-Louis Bossart wrote:
> 
> The following patches enable DisplayPort Audio on Cherrytrail machines
> when applied on top of Takashi's topic/intel-lpe-audio branch (tested
> on Zotac PI330)
> 
> There are a couple of opens where I could use some help:
>  - is it necessary to set a valid_bit which is used only for DP audio?
>  - is the sequence to set the chicken bits and unmute the amplifier ok or
> can it be improved by being moved somewhere else in the i915 driver?
>  - the register offset to be used by the audio driver depends on a
> combination of port/pipe/output type. Do we need to get access to the
> pipe information and when is it available (initial trials showed the
> pipe is still invalid when the audio notification happens)
> 
> Feedback welcome!

This makes indeed the audio on DP1 working on Dell Wyse 3040.
But the output on DP3 is still broken.  Now the transfer stalls.
No wonder, as you changed the config base to A from C.

I could make the config base changing per pipe, and now the stream
flows on DP3, too.  Alas, still no audio out.

I'll send out my patchset on top of yours.


thanks,

Takashi