[alsa-devel] HDMI hotplug on Skylake when power well is off

[Takashi Iwai]

On Fri, 17 Jul 2015 13:17:24 +0200,
Vinod Koul wrote:
> 
> On Thu, Jul 16, 2015 at 03:57:03PM +0200, Takashi Iwai wrote:
> > > >>> Yes.  This was supposed to work with WAKEEN bits, but this didn't work
> > > >>> as expected, after all.
> > > 
> > > But this applies only to HDMI codecs and the power well, right? Analog 
> > > controllers could go into D3 and WAKEEN would wake them up? Or did we 
> > > never get that working either?
> > 
> > Well, the analog codec wakeup never worked in my tests.  Maybe some
> > hardware works, who knows.
> So essentialy both for analog and hdmi this never works reliably ?

No machines worked on my test machines, so far.

> I was under the impression taht this was working okay
> 
> > > Anyhow, I went searching in the video drivers for things to match on, 
> > > inspired by your thoughts about submitting information from the graphics 
> > > driver to the audio driver. See new attached patch (still writing blind 
> > > drafts). Let me know what you think.
> > 
> > Thanks, this looks promising!
> > 
> > > I think "connector->name" seems what the most reasonable thing to export 
> > > to userspace to indicate what gfx output is related to which audio nid, 
> > > and the port being what maps 1-to-1 to a nid - we'll use that for our 
> > > own lookup (this lookup might differ between hardware generations).
> > 
> > Yeah, this mapping is the unresolved mystery.  This mythos has to be
> > revealed by Intel people.
> Are you talking about nid to connctor name mapping or something else?

Yes.


Takashi