[alsa-devel] [PATCH 1/2] ALSA: hda - Enable i915 binding for gen3/4 HDMI/DP

[Takashi Iwai]

On Thu, 31 Mar 2016 14:30:26 +0200,
Ville Syrjälä wrote:
> 
> On Wed, Mar 30, 2016 at 05:46:01PM +0200, Takashi Iwai wrote:
> > This patch fills the holes and now all i915 HDMI/DP codecs are managed
> > over the audio ELD notifier, finally.  The old gen3/gen4 chips have
> > usually only a single pin/converter pair, and the digital port mapping
> > is fixed.
> > 
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> >  sound/hda/hdac_i915.c      | 11 +++++++++++
> >  sound/pci/hda/patch_hdmi.c | 21 +++++++++++++++------
> >  2 files changed, 26 insertions(+), 6 deletions(-)
> > 
> > diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
> > index d0da2508823e..c62a9f830b84 100644
> > --- a/sound/hda/hdac_i915.c
> > +++ b/sound/hda/hdac_i915.c
> > @@ -128,6 +128,9 @@ EXPORT_SYMBOL_GPL(snd_hdac_get_display_clk);
> >   * Pin Widget 4 - PORT B (port = 1 in i915 driver)
> >   * Pin Widget 5 - PORT C (port = 2 in i915 driver)
> >   * Pin Widget 6 - PORT D (port = 3 in i915 driver)
> > + *
> > + * on earlier models:
> > + * Pin Widget 3 - PORT B
> 
> Hmm. ctg/elk have potentially multiple HDMI ports. Although they only
> have one video DIP block so can send infoframes only to one of the ports
> at a time. I wonder how this relates to the audio part, as in does the
> pin widget 3 always map to the port that is getting infoframes
> currently? I do have one elk with two HDMI ports here so I could do some
> experiments if needed.

That's great.  I'd like to see how many audio pins are there.
Could you take alsa-info.sh snapshot without my patches?
If the port switching happens but it's not seen in the audio side,
we'd need to record the last active audio port in i915 side and let
i915 function taking it (e.g. when port = -1 is passed by callback).

> >   */
> >  static int pin2port(struct hdac_device *codec, hda_nid_t pin_nid)
> >  {
> > @@ -139,6 +142,14 @@ static int pin2port(struct hdac_device *codec, hda_nid_t pin_nid)
> >  	case 0x80862882: /* VLV */
> >  		base_nid = 3;
> >  		break;
> > +	case 0x80862801: /* Bearlake */
> 
> Hmm. I wonder if this is bearlake-C or something earlier. BLC doesn't
> actually exist AFAIK, and earlier bearlake is gen3 and doesn't even
> support native HDMI output so not sure what this is doing here.

Possibly wrongly named.  Looking at the history, it seems to be
labeled as "G45 DEVBLC" originally.  I only checked Cantiga and
Eaglelake, so far.

> > +	case 0x80862802: /* Cantiga */
> > +	case 0x80862803: /* Eaglelake */
> > +	case 0x80862880: /* CedarTrail */
> 
> Cedartrail is some powervr atom thing. Should have nothing to do with i915.

Thanks, this one should be removed.

> > +	case 0x808629fb: /* Crestline HDMI */
> 
> CL is gen4 and we don't support native HDMI output on those. Strangely
> enough our spec says CL/BW do support TMDS encoding on the SDVO/HDMI
> ports and that CL also has the video DIP block and the HDA registers.
> Not sure what to make of that really.

Hm, OK, in a safer side, we may revert for these entries.


Takashi