Re: [PATCH v3 3/4] ALSA: hda - display audio call ncts callback

Yang, Libin
2015-08-11T02:51:44Z

Hi Jani,

> -----Original Message-----
> From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
> Sent: Monday, August 10, 2015 8:03 PM
> To: Yang, Libin; alsa-devel@alsa-project.org; tiwai@suse.de; intel-
> gfx@lists.freedesktop.org; daniel.vetter@ffwll.ch
> Subject: Re: [Intel-gfx] [PATCH v3 3/4] ALSA: hda - display audio call
> ncts callback
>
> On Mon, 10 Aug 2015, libin.yang@intel.com wrote:
> > From: Libin Yang <libin.yang@intel.com>
> >
> > On some Intel platforms, display audio need set N/CTS
> > manually at some TMDS frequencies.
> >
> > Signed-off-by: Libin Yang <libin.yang@intel.com>
> > ---
> > sound/pci/hda/patch_hdmi.c | 23 +++++++++++++++++++++++
> > 1 file changed, 23 insertions(+)
> >
> > diff --git a/sound/pci/hda/patch_hdmi.c
> b/sound/pci/hda/patch_hdmi.c
> > index a97db5f..918435e 100644
> > --- a/sound/pci/hda/patch_hdmi.c
> > +++ b/sound/pci/hda/patch_hdmi.c
> > @@ -1770,6 +1770,16 @@ static bool
> check_non_pcm_per_cvt(struct hda_codec *codec, hda_nid_t cvt_nid)
> > return non_pcm;
> > }
> >
> > +/* There is a fixed mapping between audio pin node and display
> port
> > + * on current Intel platforms:
> > + * Pin Widget 5 - PORT B (port = 1 in i915 driver)
> > + * Pin Widget 6 - PORT C (port = 2 in i915 driver)
> > + * Pin Widget 7 - PORT D (port = 3 in i915 driver)
> > + */
> > +static int intel_pin2port(hda_nid_t pin_nid)
> > +{
> > + return pin_nid - 4;
> > +}
> >
> > /*
> > * HDMI callbacks
> > @@ -1786,6 +1796,8 @@ static int
> generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
> > int pin_idx = hinfo_to_pin_index(codec, hinfo);
> > struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
> > hda_nid_t pin_nid = per_pin->pin_nid;
> > + struct snd_pcm_runtime *runtime = substream->runtime;
> > + struct i915_audio_component *acomp = codec->bus-
> >core.audio_component;
> > bool non_pcm;
> > int pinctl;
> >
> > @@ -1802,6 +1814,17 @@ static int
> generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
> > intel_not_share_assigned_cvt(codec, pin_nid, per_pin-
> >mux_idx);
> > }
> >
> > + /* Set N/CTS for HSW, BDW and SKL platforms.
> > + * These platforms need call set_ncts to set the N/CTS manually,
> > + * otherwise there is no sound in some sample rates.
> > + */
> > + if (is_haswell_plus(codec)) {
>
> Maybe you should move this check to the graphics side, and do the call
> whenever the callback is non-NULL, and you can be sure of the pin-
> >port
> mapping?

OK, I will remove this check here.

We have checked with silicon team for the mapping.

>
> > + /* Todo: add DP1.2 MST audio support later */
> > + if (acomp && acomp->ops && acomp->ops->set_ncts)
> > + acomp->ops->set_ncts(acomp->dev,
> > + intel_pin2port(pin_nid),
> > + 0, runtime->rate);
> > + }
> > non_pcm = check_non_pcm_per_cvt(codec, cvt_nid);
> > mutex_lock(&per_pin->lock);
> > per_pin->channels = substream->runtime->channels;
> > --
> > 1.9.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Jani Nikula, Intel Open Source Technology Center